Publications by year
2009
Walling DE, Schuller P, Zhang Y, Iroume A (2009). Extending the timescale for using beryllium 7 measurements to document soil redistribution by erosion.
Water Resources Research,
45Abstract:
Extending the timescale for using beryllium 7 measurements to document soil redistribution by erosion
The need for spatially distributed information on soil mobilization, transfer, and deposition within the landscape by erosion has focused attention on the potential for using fallout radionuclides (i.e. Cs-137, excess Pb-210, and Be-7) to document soil redistribution rates. Whereas Cs-137 and excess Pb-210 are used to estimate medium- and longer-term erosion rates (i.e. approximately 45 years and 100 years, respectively), Be-7, by virtue of its short half-life (53 days), provides potential for estimating short-term soil redistribution on bare soils. However, the approach commonly used with this radionuclide means that it can only be applied to individual events or short periods of heavy rain. In addition, it is also frequently difficult to ensure that the requirement for spatially uniform Be-7 inventories across the study area immediately prior to the study period is met. If the existing approach is applied to longer periods with several rainfall events (e. g. several weeks or more) soil redistribution is likely to be substantially underestimated. These problems limit the potential for using the Be-7 approach, particularly in investigations where there is a need to assemble representative information on soil redistribution occurring during the entire wet season. This paper reports the development of a new or refined model for converting radionuclide measurements to estimates of soil redistribution (conversion model) for use with Be-7 measurements, which permits much longer periods to be studied. This refined model aims to retain much of the simplicity of the existing approach, but takes account of the temporal distribution of both Be-7 fallout and erosion during the study period and of the evolution of the Be-7 depth distribution during this period. The approach was successfully tested using Be-7 measurements from a study of short-term soil redistribution undertaken within an area of recently harvested forest located near Valdivia in Southern Chile. The study period extended over about 3 months and included the main part of the winter wet season of 2006. The estimates of soil redistribution obtained using the new conversion model were consistent with those obtained from erosion pins deployed within the same study area and were two to three times greater than those obtained using the approach and conversion model employed in existing studies.
Abstract.
Ballantine D, Walling DE, Leeks GJL (2009). Mobilisation and Transport of Sediment-Associated Phosphorus by Surface Runoff.
WATER AIR SOIL POLL,
196(1-4), 311-320.
Abstract:
Mobilisation and Transport of Sediment-Associated Phosphorus by Surface Runoff
Surface runoff transporting sediment with high phosphorus ( P) concentrations has been identified as a major hydrological pathway for sediment-associated P delivery to surface waters and is considered a major threat to water quality, due to the ability of P to cause eutrophication in fresh water. Not all P-rich sediment that is mobilised by erosion will however be delivered directly to the channel. Some may instead be deposited in intermediate storage away from its source area. The aim of this contribution was to determine the influence of land use and soil type on the P content of surface runoff sediment and sediment deposited in intermediate storage and was undertaken in the largely agricultural and rural catchments of the Rivers Frome and Piddle in Dorset, UK. The study formed part of a larger investigation of hydrological and hydrogeochemical processes and fluxes in lowland permeable catchments in the UK (LOCAR). Soil samples were collected from the main land use types; freshly deposited sediment was sampled from ditches, hedge boundaries and depressions in fields, and sediment-laden runoff was collected during heavy rainfall events. The concentrations of total phosphorus (TP) and the P fractions found in the surface runoff sediment were significantly different from those measured in the original source soils, with a greater degree of enrichment associated with surface runoff sediment from cultivated land than from pasture land. For cultivated land, concentrations of TP and the P fractions in deposited sediment were higher than those in the original source material, while for pasture soils, concentrations of TP and the P fractions tended to be lower than in the original source soils. The relative importance of the P fractions associated with surface runoff sediment and sediment deposits also differed from that for the original soil samples. Surface runoff sediment was finer than source pasture and cultivated soils, reflecting the particle size selectivity of sediment mobilisation and transport. Soil physical properties and land use can both influence the P content of surface runoff and deposited sediment.
Abstract.
2008
Williams ND, Walling DE, Leeks GJL (2008). An analysis of the factors contributing to the settling potential of fine fluvial sediment.
HYDROL PROCESS,
22(20), 4153-4162.
Abstract:
An analysis of the factors contributing to the settling potential of fine fluvial sediment
The settling. potential of fine sediment is known to be influenced by particle size, shape. density and porosity. and is commonly predicted Stokes's law. despite its known limitations for modelling the behaviour of natural particles. In order to develop an improved Understanding of the potential for tine sediment to settle out of suspension or undergo transport by hydraulic processes. it is important to examine the role of particle structure in detail. In this study, stepwise regression was used to identify which structural properties of particles exert an important control on fine sediment behaviour in river systems. The presence of composite particles and then associated particle size. Porosity and fractal dimension were shown to be the most important controls oil settling potential. Composite particles that form in the aquatic environment (flocs) were shown to have significantly different form and behaviour form composite particles of terrestrial origin (aggregates). Importantly, it was demonstrated that particle structure and bahviour exhibited consistencies between contrasting river catchments in different locations. All Understanding of the mechanisms responsible for the formation of composite particles is viewed as providing a valuable input to efforts to model the mobilisation. transport and fate of fine sediment. Copyright (C) 2008 John Wiley & Sons, Ltd.
Abstract.
Minella JPG, Walling DE, Merten GH (2008). Combining sediment source tracing techniques with traditional monitoring to assess the impact of improved land management on catchment sediment yields.
J HYDROL,
348(3-4), 546-563.
Abstract:
Combining sediment source tracing techniques with traditional monitoring to assess the impact of improved land management on catchment sediment yields
This paper aims to demonstrate the potential value of combining sediment source tracing techniques with traditional monitoring approaches, when documenting the impact of improved land management on catchment sediment yields. It reports the results of an investigation undertaken in a small (1.19 km(2)) agricultural catchment in southern Brazil, which was monitored before and after the implementation of improved Land management practices. Attention focussed on 50 storm events that occurred between May 2002 and March 2006 and which reflected the behaviour of the catchment during the pre-change, transition and post-change periods. Improved [and management, involving minimum-till cultivation and the maintenance of good crop cover, was introduced in early 2003. The traditional monitoring provided a basis for evaluating the changes in storm runoff volume, storm hydrograph peak and storm-period sediment Load and mean suspended sediment concentration. The results indicate that both storm runoff volumes and peak flows associated with a given amount of rainfall provided evidence of a significant decrease after the introduction of improved land management. Storm-period sediment loads showed a similar reduction, with a reduction by as much as 80% for low magnitude events and of ca. 40% for events of intermediate magnitude. However, there was no significant change in mean suspended sediment concentrations, indicating that the reductions in sediment load were primarily the result of the reduced storm runoff volume. Sediment source fingerprinting was used to explore the changes in the relative and absolute contributions to the storm sediment loads from the three key sources, namely the surface of the fields under crops, the unpaved roads and the stream channels. A comparison of the load-weighted mean contributions for the pre- and post-treatment periods indicated that the contribution from the field surfaces and unpaved roads decreased from 63% and 36% to 54% and 24%, respectively, whereas the contribution from the stream channels increased from ca. 2% to 22%. By relating the absolute amounts of sediment mobilised from each individual source,group to variables representing the runoff and precipitation associated with the events, it was possible to identify changes in the response of the individual sediment sources to the changes in land management that occurred within the catchment. Sediment mobilisation from the stream channel during individual events increased substantially over the whole range of flows after the introduction of improved land management in the study catchment, whereas the amounts of sediment mobilised from the surfaces of the fields and the unpaved roads showed a significant decrease during events of low and intermediate magnitude. The short monitoring period associated with the study, coupled with inter-annual variations in rainfall, necessarily limit the scope and rigour of the study reported, but it is seen to provide a useful demonstration of how the coupling of sediment source tracing with more traditional monitoring techniques can provide an improved understanding of the impact of improved management practices on the sediment response of a catchment, as well as important information to inform the design and implementation of effective sediment management and control measures. (c) 2007 Elsevier B.V. All rights reserved.
Abstract.
Mabit L, Benmansour M, Walling DE (2008). Comparative advantages and limitations of the fallout radionuclides Cs-137, Pb-210(ex) and Be-7 for assessing soil erosion and sedimentation.
J ENVIRON RADIOACTIV,
99(12), 1799-1807.
Abstract:
Comparative advantages and limitations of the fallout radionuclides Cs-137, Pb-210(ex) and Be-7 for assessing soil erosion and sedimentation
The fallout radionuclides (FRNs) Cs-137, Pb-210(ex) and Be-7 are increasingly being used as a means of obtaining quantitative information on soil erosion and sediment redistribution rates within agricultural landscapes, over a range of different timescales, and they are frequently seen to represent a valuable complement to conventional measurement techniques. The recent development of the Be-7 method has greatly extended the timescale over which FRNs can be used, by permitting assessment of short-term soil erosion linked to individual events and changing soil management practices. This paper aims to review the advantages and limitations of each of the three FRNs and to identify key knowledge gaps linked to their use. In addition, guidelines for selecting the most appropriate FRN and associated approach, in order to deal with a range of spatial and temporal scales and to investigate specific sets of agro-environmental problems, are provided. Key requirements for future work, related to the application of FRNs in soil erosion investigations, are also identified. These include the upscaling of the approach to the catchment scale and a shift from use of the approach as a research tool to a decision support tool. (C) 2008 Elsevier Ltd. All rights reserved.
Abstract.
Fukuyama T, Onda Y, Takenaka C, Walling DE (2008). Investigating erosion rates within a Japanese cypress plantation using Cs-137 and Pb-210(ex) measurements.
J GEOPHYS RES-EARTH,
113(F2).
Abstract:
Investigating erosion rates within a Japanese cypress plantation using Cs-137 and Pb-210(ex) measurements
In Japan, soil erosion represents an important threat to the longer-term sustainability of Japanese cypress plantations. Although it has been demonstrated that raindrop impact, rather than sheet or rill/gully erosion, is the dominant process in both sediment detachment and sediment transport at the point or hillslope scale in such plantations, the role of overland flow at the catchment scale has received little attention to date. To confirm the dominant erosion process operating in a Japanese cypress plantation catchment, we predicted the sediment transport capacities of both overland flow, expressed as a function of the upslope contributing area and the local slope gradient, and rainsplash, expressed as a topographic curvature, for 45 sampling points across the catchment. In addition, we compared the predicted values of sediment transport capacity and rainsplash with the erosion rates estimated using Cs-137 and Pb-210(ex) measurements. The results indicated a close correspondence between the local transport capacity of overland flow and the local erosion rates estimated using the radionuclide measurements. In contrast, there was no significant correlation between the topographic curvature and the erosion rates. Furthermore, the average radionuclide inventories for the catchment were much smaller than the local reference inventories, indicating net loss of eroded soil and radionuclides from the catchment. These results suggest that overland flow makes a significant contribution to surface soil erosion even on forested hillslopes. In addition, the results provide a useful demonstration of the potential for using radionuclide measurements to produce independent information on long-term erosion rates, which can be used for investigating erosion processes and validating erosion models.
Abstract.
Brown AG, Carpenter RG, Walling DE (2008). Monitoring the fluvial palynomorph load in a lowland temperate catchment and its relationship to suspended sediment and discharge.
HYDROBIOLOGIA,
607, 27-40.
Abstract:
Monitoring the fluvial palynomorph load in a lowland temperate catchment and its relationship to suspended sediment and discharge
Despite it being a component of the seston we know very little about fluvial (waterborne) pollen and spore (palynomorph) transport. This paper presents the results of a monitoring programme conducted over two years and at a catchment scale in South West England. A hierarchical monitoring network was established with flood peak samples taken at 9 sub-catchments, intra-hydrograph samples taken in two sub-catchments and time-integrated sampling undertaken at one location. In addition sampling was undertaken of probable palynomorph sources such as channel bed and bank sediments, and the airborne pollen flux was monitored using modified Tauber traps. The results support previous research in illustrating how the vast majority of fluvial pollen and spores are transported during floods (91%) and that the main control on waterborne palynomorph assemblages is the catchment vegetation and its spatial distribution but with a long-distance (extra-catchment) component. However, strong seasonal effects are also shown, and the importance of distinctive sources such as the riparian input, bed re-suspension and overland flow into drains and tributaries is revealed. Fine sediment in river pools appears to act as a selective store of damaged cereal type pollen grains derived from arable fields. Although pollen does form part of composite particles the data presented here suggest that the majority of the pollen is transported as single grains. Fluvial palynomorph loading is strongly dependant upon discharge and so concentrations in laminated or varved sediments could be regarded as a proxy for flood magnitude.
Abstract.
Golosov V, Sidorchuk A, Walling DE (2008). Nikolay I. Makkaveev and the development of Fluvial Geomorphology in Russia and the former Soviet Union.
CATENA,
73(1), 146-150.
Abstract:
Nikolay I. Makkaveev and the development of Fluvial Geomorphology in Russia and the former Soviet Union
2008 marks the centenary of the birth of Professor Nikolay Ivanovich Makkaveev (1908-1983), a former Professor in the Faculty of Geography at Moscow State University and the founder of the Laboratory of Soil Erosion and Fluvial Processes in the Faculty of Geogaphy.Professor Makkaveev is little known in the west, but he must be seen as a highly influential and important figure in the development of fluvial geomorphology in Russia and the former Soviet Union. He was responsible for drawing together the nascent work on fluvial geomorphology in Russia, which was founded in the different fields of soil science and soil conservation and waterway engineering, and his monograph entitled 'The river channel and erosion in its basin' published in 1955 emphasised the need for a holistic treatment of the river and its drainage basin. In advocating a holistic systems approach, Makkaveev's ideas paralleled similar developments in the west and anticipated future recognition of the importance of an understanding of the geomorphological functioning of drainage basins for effective catchment and river basin management. Makkaveev's ideas were highly influential in the development of research in fluvial geomorphology in Russia and the former Soviet Union and the Laboratory of Soil Erosion and Fluvial Processes that he founded within Moscow State University remains a highly successful and influential focus of fluvial geomorphological research in Russia. (C) 2007 Elsevier B.V. All rights reserved.
Abstract.
Piegay H, Hupp CR, Citterio A, Dufour S, Moulin B, Walling DE (2008). Spatial and temporal variability in sedimentation rates associated with cutoff channel infill deposits: Ain River, France.
WATER RESOUR RES,
44(5).
Abstract:
Spatial and temporal variability in sedimentation rates associated with cutoff channel infill deposits: Ain River, France
Floodplain development is associated with lateral accretion along stable channel geometry. Along shifting rivers, the floodplain sedimentation is more complex because of changes in channel position but also cutoff channel presence, which exhibit specific overflow patterns. In this contribution, the spatial and temporal variability of sedimentation rates in cutoff channel infill deposits is related to channel changes of a shifting gravel bed river (Ain River, France). The sedimentation rates estimated from dendrogeomorphic analysis are compared between and within 14 cutoff channel infills. Detailed analyses along a single channel infill are performed to assess changes in the sedimentation rates through time by analyzing activity profiles of the fallout radionuclides Cs-137 and unsupported Pb-210. Sedimentation rates are also compared within the channel infills with rates in other plots located in the adjacent floodplain. Sedimentation rates range between 0.65 and 2.4 cm a(-1) over a period of 10 to 40 years. The data provide additional information on the role of distance from the bank, overbank flow frequency, and channel geometry in controlling the sedimentation rate. Channel infills, lower than adjacent floodplains, exhibit higher sedimentation rates and convey overbank sediment farther away within the floodplain. Additionally, channel degradation, aggradation, and bank erosion, which reduce or increase the distance between the main channel and the cutoff channel aquatic zone, affect local overbank flow magnitude and frequency and therefore sedimentation rates, thereby creating a complex mosaic of sedimentation zones within the floodplain and along the cutoff channel infills. Last, the dendrogeomorphic and Cs-137 approaches are cross validated for estimating the sedimentation rate within a channel infill.
Abstract.
Walling DE, Collins AL (2008). The catchment sediment budget as a management tool.
ENVIRON SCI POLICY,
11(2), 136-143.
Abstract:
The catchment sediment budget as a management tool
There is increasing recognition that fine sediment represents an important diffuse source pollutant in surface waters, due to its role in governing the transfer and fate of many substances, including nutrients, heavy metals, pesticides and other organic contaminants, and because of its impacts on aquatic ecology. Catchment management strategies therefore frequently need to include provision for the control of sediment mobilisation and delivery. The sediment budget concept provides a valuable framework for assisting the management and control of diffuse source sediment pollution and associated problems, by identifying the key sources and demonstrating the importance of intermediate stores and the likely impact of upstream mitigation strategies on downstream suspended sediment and sediment-associated contaminant fluxes. Accordingly, the utility of the sediment budget concept for catchment management is further discussed, by introducing examples from several contrasting river basins. (C) 2007 Elsevier Ltd. All rights reserved.
Abstract.
Walling DE (2008). The changing sediment load of the Mekong River.
Ambio,
37(3), 150-157.
Abstract:
The changing sediment load of the Mekong River.
The sediment loads of many of the world's major rivers have changed significantly in recent years due to land-use change, reservoir construction, and other human impacts on their drainage basins. For many rivers, the loads have decreased, whereas for others, they have increased. Such changes can have important implications for both the natural functioning of the system as well as for human exploitation of the river system. This paper considers the evidence for recent changes in the sediment load of the Mekong River. The available data have a number of limitations in terms of both sampling frequency and the period of coverage, but they have been processed to provide a basis for considering the changes in the sediment load of the river over the period extending from the early 1960s to 2002. Although there is evidence of increasing loads at some measuring stations, the overall trends show little evidence of major changes, and the system provides evidence of buffering through storage. As of 2002, the construction of major dams on the headwaters in China appears to have had little impact on the sediment load, although as further larger dams are commissioned, the sediment load of the Mekong can be expected to decrease.
Abstract.
Author URL.
Ballantine DJ, Walling DE, Collins AL, Leeks GJL (2008). The phosphorus content of fluvial suspended sediment in three lowland groundwater-dominated catchments.
J HYDROL,
357(1-2), 140-151.
Abstract:
The phosphorus content of fluvial suspended sediment in three lowland groundwater-dominated catchments
This paper reports an investigation of the phosphorus (P) content of fluvial. suspended sediment samples collected from three lowland groundwater-dominated agricultural catchments in the UK. In-stream trap samplers were installed at a total of 21 locations in the catchments of the Rivers Frome and Piddle in Dorset and in the Upper Tern in Shropshire, UK. Time-integrated suspended sediment samples (n = 187) were collected at regular intervals over a period of 22 months and analysed for total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP) and algal available phosphorus (AAP). TP concentrations varied between sampling sites in the Rivers Frome and Piddle, allowing key P inputs to be identified, while fractionation of P assisted in identifying the nature of these inputs. There was also significant variation in both the TP concentration and the concentration of individual. fractions between the Frome and Piddle catchments and the Upper Tern. These contrasts were attributed to the differing underlying geologies, since the Frome and Piddle are underlain predominantly by chalk, whilst the Upper Tern is underlain by sandstone, and also to the different soil types present. The TP content of suspended sediment collected from the Frome catchment showed a statistically significant relationship with specific surface area, but this relationship was not found for the remaining catchments. Temporal variation in P concentrations at both the seasonal and event scale was also investigated. Seasonal variations were noted for TP concentrations and for the concentrations of IP, OP and AAP in all the study catchments, but no consistent seasonal patterns were discernible. Maximum and minimum concentrations of the individual fractions occurred during different months in each of the study catchments, suggesting that different controls operated in the individual catchments. Short-term temporal variations in TP concentrations were documented for two high flow events. Concentrations were tower during high flow events than in baseflow, reflecting dilution. (C) 2008 Elsevier B.V. All rights reserved.
Abstract.
Walling DE, Collins AL, Stroud RW (2008). Tracing suspended sediment and particulate phosphorus sources in catchments.
J HYDROL,
350(3-4), 274-289.
Abstract:
Tracing suspended sediment and particulate phosphorus sources in catchments
Information on suspended sediment and particulate P (PP) sources is an important requirement in many catchment-based diffuse source pollution studies, in order to assist with model validation and to provide information to support the development of effective sediment and phosphorus control strategies. Such information is, however, frequently unavailable or difficult to assemble. In the study reported, source fingerprinting procedures were successfully used to assemble this information for seven sub-catchments in the Hampshire Avon catchment and five sub-catchments in the Middle Herefordshire Wye catchment. The results provide important new information on the relative importance of the contributions from surface and channel/subsurface sources to the suspended sediment and PP fluxes from the catchments. In the Wye sub-catchments channel/subsurface sources contributed 40-55% of the overall suspended sediment flux and 21-43% of the PP flux from the catchments. Equivalent values for the Avon were 1-41% and 154%, respectively. Combination of the information on the relative importance of surface and channel/subsurface sources with measured suspended sediment fluxes has provided the first estimates of the specific fluxes of sediment and PP attributable to channel/subsurface sources for UK catchments. The former are as high as 15-20 t km(-2) year(-1) in some of the Wye sub-catchments, whereas the latter exceeded 0.1 kgP ha(-1) year(-1) in the same sub-catchments. The results emphasize the need to take account of potential contributions from channel/subsurface sources when using measured suspended sediment and PP flux data to validate predictions derived from models incorporating only surface contributions. (C) 2007 Elsevier B.V. All rights reserved.
Abstract.
Sepulveda A, Schuller P, Walling DE, Castillo A (2008). Use of Be-7 to document soil erosion associated with a short period of extreme rainfall.
J ENVIRON RADIOACTIV,
99(1), 35-49.
Abstract:
Use of Be-7 to document soil erosion associated with a short period of extreme rainfall
Intensification and expansion of agricultural production since the 1970s have increased soil erosion problems in south-central Chile. Quantitative information on soil loss is needed for erosion risk assessment and to establish the effectiveness of improved land management practices. Since information from traditional sources, such as erosion plots, is limited, attention has been directed to the use of environmental radionuclides for documenting erosion rates. Cs-137 has been successfully utilised for this purpose, but only provides information on medium-term erosion rates. There is also a need to document event-related soil erosion. This paper outlines the basis for using Be-7 measurements to document short-term erosion and reports its successful use for quantifying the erosion that occurred within an arable field, as a result of a period of heavy rainfall (400 mm in 27 days) occurring in May 2005. The study field had been under a no-till, no-burning system for 18 years, but immediately prior to the period of heavy rainfall the harvest residues were burnt. The erosion recorded therefore reflected both the extreme nature of the rainfall and the effects of the burning in increasing surface runoff and erosion. The sampled area corresponded to that used previously by the authors to document the medium-term erosion rates associated with both conventional tillage and the subsequent switch to a no-till system. Comparisons between the erosion documented for the period of heavy rainfall in 2005 with these medium-term erosion rates permits some tentative conclusions regarding the importance of extreme events and the impact of burning in increasing the erosion associated with the no-till system. (c) 2007 Elsevier Ltd. All rights reserved.
Abstract.
2007
Schuller P, Walling DE, Sepulveda A, Castillo A, Pino I (2007). Changes in soil erosion associated with the shift from conventional tillage to a no-tillage system, documented using (CS)-C-137 measurements.
SOIL TILL RES,
94(1), 183-192.
Abstract:
Changes in soil erosion associated with the shift from conventional tillage to a no-tillage system, documented using (CS)-C-137 measurements
Caesium-137 measurements have been used to document changes in the rate and extent of soil erosion associated with the shift from conventional tillage to a no-till system on a farm in south-central Chile. The study site is located in the Coastal Mountains of the 9th Region (38 degrees 37'S 73 degrees 04'W), and is characterized by Araucano series Ultisols (Typic Hapludult), a temperate climate and a mean annual precipitation of 1100 mm year(-1). A field, which was under conventional tillage until May 1986 and which was subsequently managed using a no-till system, was selected for the study. An approach for using (CS)-C-137 measurements to quantify the medium-term erosion and deposition rates associated with the periods of contrasting land management documented previously was employed. This approach involves both a standard method and a simplified method, which permits a target-number of sampling points to be used. In this study, emphasis was placed on application of the simplified method, which has the important advantage of requiring only two (CS)-C-137 measurements per sampling point. The results obtained for the study field showed that the implementation of no-till practices, including crop residue management, coincided with a reduction in the net erosion rate by about 87% and the proportion of the study area subject to erosion from 100% to 57%, and therefore significantly decreased soil and nutrient loss. Reduced soil and nutrient loss has important on-site benefits, in terms of sustainable management of the soil resource and maintaining crop productivity, as well as reducing off-site problems associated with the degradation of river water quality. (c) 2006 Elsevier B.V. All rights reserved.
Abstract.
Woodward JC, Walling DE (2007). Composite suspended sediment particles in river systems: their incidence, dynamics and physical characteristics.
HYDROL PROCESS,
21(26), 3601-3614.
Abstract:
Composite suspended sediment particles in river systems: their incidence, dynamics and physical characteristics
Most of the existing data on the effective particle size characteristics of fluvial suspended sediment derive from instantaneous sampling methods that may not be representative of the overall suspended sediment loads. This presents difficulties when there is a need to incorporate effective particle size data into numerical models of floodplain sedimentation and sediment-associated, contaminant transfer. We have used a field-based water elutriation apparatus (WEA) to assemble a large (36 flood) database on the time-integrated nature of the effective and absolute particle size characteristics of suspended sediment in four subcatchments of the River Exe basin of southwest England. These catchments encompass a wide range of terrains and fluvial environments that are broadly representative of much of the UK and temperate, low relief northwest Europe. The WEA provides important data on the physical characteristics of composite particles that are not attainable using other methods. This dataset has allowed, for the first time, detailed interbasin comparisons of the time-integrated particle size characteristics of suspended sediment and reliable estimates of the contribution of five effective size classes to the mean annual suspended sediment load of the study catchments. The suspended sediment load of each river is dominated by composite rather than primary particles, with, for example, almost 60% (by mass) of the sediment load of the River Exe at Thorverton transported as composite particles > 16 mu m in size. All the effective size classes contain significant clay components. A key outcome of this study is the recognition that each catchment has a distinctive time-integrated effective particle size signature. In addition, the time-integrated effective particle size characteristics of the suspended loads in each of the catchments display much greater spatial variability than the equivalent absolute particle size distributions. This indicates that the processes producing composite particles vary significantly between these catchments, and this has important implications for our understanding of the dynamics of suspended sediment properties. Copyright (C) 2007 John Wiley & Sons, Ltd.
Abstract.
Petticrew EL, Krein A, Walling DE (2007). Evaluating fine sediment mobilization and storage in a gravel-bed river using controlled reservoir releases.
HYDROL PROCESS,
21(2), 198-210.
Abstract:
Evaluating fine sediment mobilization and storage in a gravel-bed river using controlled reservoir releases
Two controlled flow events were generated by releasing water from a reservoir into the Olewiger Bach, located, near Trier, Germany. This controlled release of near bank-full flows allowed an investigation of the fine sediment (< 63 mu m) mobilized from channel storage. Both a winter (November) and a summer (June) release event were generated, each having very different antecedent flow conditions. The characteristics of the release hydrographs and the associated sediment transport indicated a reverse hysteresis with more mass, but smaller grain sizes, moving on the falling limb. Fine sediment stored to a depth of 10 cm in the gravels decreased following the release events, indicating the dynamic nature and importance of channel-stored sediments as source materials during high flow events. Sediment traps, filled with clean natural gravel, were buried in riffles before the release of the reservoir water and the total mass of fine sediment collected by the traps was measured following the events. Twice the mass of fine sediment was retained by the gravel traps compared with the natural gravels, which may be due to their altered porosity. Although the amount of fine sediment collected by the traps was not significantly related to measures of gravel structure, it was found to be significantly correlated to measures of local flow velocity and Fronde number, a portion of the traps were fitted with lids to restrict surface exchange of water and sediment. These collected the highest amounts of event-mobilized sediments, indicating that inter-gravel lateral flows, not just surface infiltration of sediments, are important in replenishing and redistributing the channel-stored fines. These findings regarding the magnitude and direction of fine sediment movement in gravel beds are significant in both a geomorphic and a biological context. Copyright (c) 2006 John Wiley & Sons, Ltd.
Abstract.
Collins AL, Walling DE (2007). Fine-grained bed sediment storage within the main channel systems of the Frome and Piddle catchments, Dorset, UK.
HYDROL PROCESS,
21(11), 1448-1459.
Abstract:
Fine-grained bed sediment storage within the main channel systems of the Frome and Piddle catchments, Dorset, UK
Lowland permeable catchments in the UK are particularly prone to sedimentation problems, on account of the increased fine sediment loadings generated by recent land-use change and their stable seasonal hydrological regimes, which are frequently depleted by groundwater abstraction. Fine-grained sediment storage on the bed of the main channel systems of the Frome (437 km(2)) and Piddle (183 km(2)) catchments, Dorset, UK, has been examined at 29 sites using a sediment remobilization technique. Measurements encompassed the period February 2003-July 2004. At individual sites in the Frome, average values ranged between 410 and 2630 g m(-2), with an overall mean of 918 g m(-2). In the Piddle, the average values for individual sites varied between 260 and 4340 g m(-2), with an overall mean of 1580 g m(-2). Temporal variations in fine bed sediment storage at each site were appreciable, with the coefficients of variation ranging between 43 and 155% in the Frome and between 33 and 160% in the Piddle. Average reach-scale specific bed sediment storage increased markedly downstream along each main stem from 2 to 29 1 km(-1) (Frome) and from 4 to 19 1 km(-1) (Piddle). Total fine sediment storage on the channel bed of the Frome varied between 479 t (5 t km(-1)) and 1694 t (17 t km(-1)), with a mean of 795 t (7 t km(-1)), compared with between 371 t (5 t km(-1)) and 1238 t (14 t km(-1)) with a mean of 730 t (9 t km(-1)) in the Piddle. During the study period, fine bed sediment storage was typically equivalent to 18% (Frome) and 57% (Piddle) of the mean annual suspended sediment flux at the study catchment outlets. Copyright (c) 2006 John Wiley & Sons, Ltd.
Abstract.
Williams ND, Walling DE, Leeks GJL (2007). High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment.
Water Res,
41(5), 1081-1093.
Abstract:
High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment.
This paper reports the use of a LISST-100 device to monitor the effective particle size characteristics of suspended sediment in situ, and at a quasi-continuous temporal resolution. The study site was located on the River Exe at Thorverton, Devon, UK. This device has not previously been utilized in studies of fluvial suspended sediment at the storm event scale, and existing studies of suspended sediment dynamics have not involved such a high temporal resolution for extended periods. An evaluation of the field performance of the instrument is presented, with respect to innovative data collection and analysis techniques. It was found that trends in the effective particle size distribution (EPSD) and degree of flocculation of suspended sediment at the study site were highly complex, and showed significant short-term variability that has not previously been documented in the fluvial environment. The collection of detailed records of EPSD facilitated interpretation of the dynamic evolution of the size characteristics of suspended sediment, in relation to its likely source and delivery and flocculation mechanisms. The influence of measurement frequency is considered in terms of its implications for future studies of the particle size of fluvial suspended sediment employing in situ data acquisition.
Abstract.
Author URL.
Brown AG, Carpenter RG, Walling DE (2007). Monitoring fluvial pollen transport, its relationship to catchment vegetation and implications for palaeoenvironmental studies.
REV PALAEOBOT PALYNO,
147(1-4), 60-76.
Abstract:
Monitoring fluvial pollen transport, its relationship to catchment vegetation and implications for palaeoenvironmental studies
Despite being the most important source of pollen and spore input into most lakes and near-shore marine sediments, we know very little about fluvial (waterborne) pollen and spore transport. This paper presents the results of a dedicated monitoring programme conducted over 2 years and at a catchment scale in South West England. The land use of the nine sub-catchments monitored was determined using Landsat Thematic Data. At two stations, pollen and spore sampling through storm hydrographs was undertaken whilst at the other 7 sub-catchments only peak flow samples were collected. Samples were also collected from re-suspended bed material, riverbanks and at low flows. Airborne pollen flux was monitored using modified Tauber traps. The results support previous research illustrating how the vast majority of fluvial pollen and spores are transported during floods (in this case 9 1 %) and that the main control on waterbome pollen and spore assemblages is the catchment vegetation. However, strong seasonal effects are shown as well as the importance of distinctive sources, such as the riparian input, bed re-suspension and overland flow into drains and tributaries. Fine sediment in river pools appears to act as a selective store of damaged cereal-type pollen grains in arable catchments and this can reduce the inherent underestimate of arable land from pollen diagrams with a high fluvial input and increase the visibility of early agriculture. in order to simulate the likely result of a flood-dominated influx to a small lake scenario, modelling was undertaken whereby different sub-catchments were substituted in order to represent changes in catchment vegetation under a constant hydrological regime. The results show the dampened response of land use groups to catchment land use change, and the frequent occurrence of anomalous single-level peaks due to seasonal flushes from specific near-stream vegetation types. Both these features are commonly seen in lake pollen diagrams. Fluvial pollen and spore loading is dependant upon discharge and so concentrations in laminated or varved sediments could be regarded as a proxy for flood magnitude. The implications for this study on the interpretation of lake and near-shore marine pollen and spore diagrams are discussed and it is argued that a more quantitative approach to waterbome pollen could improve the estimation of land use from lakes in the temperate zone. (C) 2007 Elsevier B.V. All rights reserved.
Abstract.
Collins AL, Walling DE (2007). Sources of fine sediment recovered from the channel bed of lowland groundwater-fed catchments in the UK.
GEOMORPHOLOGY,
88(1-2), 120-138.
Abstract:
Sources of fine sediment recovered from the channel bed of lowland groundwater-fed catchments in the UK
Groundwater-fed, lowland permeable catchments in the UK are particularly susceptible to fine sediment accumulation on the bed of their main channel systems. Appropriate catchment management solutions are therefore required. Accurate targeting of sediment abatement strategies is, however, hampered by the dearth of reliable information on the principal sediment sources involved. In view of this, a composite fingerprinting technique, incorporating uncertainty analysis, has been used to investigate the primary sources of fine sediment samples recovered from a total of 18 individual sampling sites on the channel bed of the rivers Frome (similar to 437 km(2)) and Piddle (similar to 183 km(2)), Dorset, UK. In the Frome study catchment, mean relative contributions from areas of woodland, pasture and cultivation, and from channel banks/subsurface sources ranged between 1 +/- 1%-6 +/- 2%, 10 +/- 2%-42 +/- 2%, 44 +/- 4%-81 +/- 2% and 7 +/- 2%-19 +/- 4%, respectively. The corresponding mean relative contributions in the Piddle study area were 1 +/- 1%- 11 +/- 4% (woodland), 10 +/- 2%-28 +/- 4% (pasture), 44 +/- 2%-80 +/- 2% (cultivated) and 7 +/- 2%-21 +/- 2% (channel banks and subsurface sources). These findings have important implications for establishing a scientific basis for assisting the targeting of sediment management and control policies. (C) 2006 Elsevier B.V all rights reserved.
Abstract.
Heywood MJT, Walling DE (2007). The sedimentation of salmonid spawning gravels in the Hampshire Avon catchment, UK: implications for the dissolved oxygen content of intragravel water and embryo survival.
HYDROL PROCESS,
21(6), 770-788.
Abstract:
The sedimentation of salmonid spawning gravels in the Hampshire Avon catchment, UK: implications for the dissolved oxygen content of intragravel water and embryo survival
The accumulation of sediment within salmonid redd gravels can have a detrimental impact on the development of salmonid embryos; therefore, redd sedimentation represents a potential limiting factor for salmonid reproduction. The links between redd sedimentation, the dissolved oxygen content of intragravel water and salmonid embryo survival within the upper and middle parts of the Hampshire Avon catchment in southern England are explored. Measurements of surface and intragravel water quality and redd properties were undertaken for artificial redds constructed at known spawning sites. Salmonid embryos were also planted into artificial redds adjacent to the monitoring equipment. The rate of sedimentation of the newly cleaned redd gravels demonstrated a non-linear decrease over time, which is attributed to a particle-size-selective depositional process. The results of the study confirm that low embryo survival and low dissolved oxygen concentrations in intragravel water can be attributed to the accumulation of sediment within the redd gravels. This was found to produce a reduction in redd permeability, which limited the interchange of surface and intragravel water and, therefore, the supply of dissolved oxygen to the intragravel environment. In view of the diminished status of salmonids within many of the UK's chalk rivers and streams, the results highlight the need for management initiatives aimed at reducing redd sedimentation and thereby optimizing salmonid embryo incubation success. Copyright (c) 2006 John Wiley & Sons, Ltd.
Abstract.
Collins AL, Walling DE (2007). The storage and provenance of fine sediment on the channel bed of two contrasting lowland permeable catchments, UK.
RIVER RES APPL,
23(4), 429-450.
Abstract:
The storage and provenance of fine sediment on the channel bed of two contrasting lowland permeable catchments, UK
Fine sediment (
Abstract.
Navas A, Walling DE, Quine T, Machin J, Soto J, Domenech S, Lopez-Vicente M (2007). Variability in (CS)-C-137 inventories and potential climatic and lithological controls in the central Ebro valley, Spain.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY,
274(2), 331-339.
Abstract:
Variability in (CS)-C-137 inventories and potential climatic and lithological controls in the central Ebro valley, Spain
The extent of soil erosion in some Spanish semiarid regions has caused great concern regarding the sustainability of soil resources. Accelerated soil erosion, particularly in some Mediterranean areas, is likely to be one of the main environmental problems associated with climate change. Fallout Cs-137 has been shown to provide a reliable basis for assessing soil erosion rates in different environments around the world. However, existing information concerning the spatial variation of Cs-137 inventories at reference sites has identified a need for further investigation of the factors affecting their spatial variability in semiarid environments, where stony and skeletal soils are predominant. Reference sites at three locations in the central Ebro valley were selected to investigate the Cs-137 content of several grain size fractions. Each site included both natural vegetated conditions and cultivated land and the three sites were characterized by different values of mean annual rainfall. The results obtained demonstrate the influence of lithology, land use and climate on the spatial variability of Cs-137 inventories that increase from 1190, to 1500 and 1710 Bq center dot m(-2) with increasing annual rainfall values from 300 to 500 mm at the study sites. The soils on marls at the Valare (n) over tildea site had the highest proportion of Cs-137 in the coarse fractions of cultivated soils (12%) in comparison with soils developed on limestones at Loma Negra (5%), whereas no Cs-137 content was found in the coarse fractions of soils on glacis-terrace materials at Pe (n) over tilde aflor. The Cs-137 reference inventories are higher in soils on marls and sands at cultivated locations at Valare (n) over tildea and Pe (n) over tilde aflor, but have similar values in soils at cultivated and uncultivated locations on limestones at Loma Negra. Therefore, in absence of level undisturbed soils with natural vegetation cover, cultivated flat soils on hard rocks could provide reliable reference inventories.
Abstract.
2006
Zhang X, Qi Y, Walling DE, He X, Wen A, Fu J (2006). A preliminary assessment of the potential for using Pb-210(ex) measurement to estimate soil redistribution rates on cultivated slopes in the Sichuan Hilly Basin of China.
CATENA,
68(1), 1-9.
Author URL.
Gregory KJ, Macklin MG, Walling DE (2006). Conclusion and extension of protocol.
CATENA,
66(1-2), 184-187.
Author URL.
Zhang X, Walling DE, Yang Q, He X, Wen Z, Qi Y, Feng M (2006). Cs-137 budget during the period of 1960s in a small drainage basin on the Loess Plateau of China.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY,
86(1), 78-91.
Author URL.
Nicholas AP, Fang X, Sweet RJ, Walling DE (2006). Development and evaluation of a new catchment-scale model of floodplain sedimentation . Water Resources Research, 42(10).
Walling DE, Collins AL, Jones PA, Leeks GJL, Old G (2006). Establishing fine-grained sediment budgets for the Pang and Lambourn LOCAR catchments, UK.
Journal of Hydrology,
330(1-2), 126-141.
Abstract:
Establishing fine-grained sediment budgets for the Pang and Lambourn LOCAR catchments, UK
An integrated approach to data collection, combining the use of 137Cs measurements, sediment source fingerprinting, bed sediment surveys and conventional river monitoring, has been successfully employed to establish the fine-grained sediment budgets of two lowland groundwater-fed catchments in the UK. Gross surface erosion is higher on cultivated land (Pang: 55 263 t yr-1 or 507 t km-2 yr-1; Lambourn: 79 997 t yr-1 or 437 t km-2 yr-1) than on pasture (Pang: 1960 t yr-1 or 140 t km-2 yr-1; Lambourn: 1425 t yr-1 or 95 t km-2 yr-1) in both study areas and a substantial proportion of the mobilized sediment is sequestered within the fields (Pang: 28 058 t yr-1 or 228 t km-2 yr-1; Lambourn: 55 575 t yr-1 or 281 t km-2 yr-1) and between the individual fields and the river channel network (Pang: 28 672 t yr-1 or 233 t km-2 yr-1; Lambourn: 24 782 t yr-1 or 125 t km-2 yr-1). The sediment contribution from banks and subsurface sources is relatively low and typically ca. 5 t yr-1 in the Pang and ca. 11 t yr-1 in the Lambourn, representing only about 1% of the suspended sediment output from each study catchment. The mean level of fine-grained sediment storage in the main channel system is equivalent to 38% (Pang) and 21% (Lambourn) of the respective mean annual suspended sediment yields of the two catchments. The estimated sediment delivery ratio for both study catchments is ca. 1%. © 2006 Elsevier B.V. All rights reserved.
Abstract.
Walling DE (2006). Human impact on land-ocean sediment transfer by the world's rivers.
Author URL.
Collins AL, Walling DE (2006). Investigating the remobilization of fine sediment stored on the channel bed of lowland permeable catchments in the UK.
Author URL.
Walling, D.E. Sweet, R.J. Fang, X. (2006). New strategies for upscaling high-resolution flow and overbank sedimentation models to quantify floodplain sediment storage at the catchment scale. Journal of Hydrology, 329(3-4), 577-594.
Yang M-Y, Walling DE, Tian J-L, Liu P-L (2006). Partitioning the contributions of sheet and rill erosion using beryllium-7 and cesium-137.
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL,
70(5), 1579-1590.
Author URL.
Gregory KJ, Benito G, Dikau R, Golosov V, Johnstone EC, Jones JAA, Macklin MG, Parsons AJ, Passmore DG, Poesen J, et al (2006). Past hydrological events and global change.
HYDROLOGICAL PROCESSES,
20(1), 199-204.
Author URL.
Foster IDL, Mighall TM, Proffitt H, Walling DE, Owens PN (2006). Post-depositional Cs-137 mobility in the sediments of three shallow coastal lagoons, SW England.
JOURNAL OF PALEOLIMNOLOGY,
35(4), 881-895.
Author URL.
Walling DE, Fang D, Nicholas AP, Sweet RJ (2006). River flood plains as carbon sinks.
Abstract:
River flood plains as carbon sinks
Abstract.
Hasholt B, Bobrovitskaya N, Bogen J, McNamara J, Mernild SH, Milburn D, Walling DE (2006). Sediment transport to the Arctic Ocean and adjoining cold oceans.
Author URL.
Carter J, Walling DE, Owens PN, Leeks GJL (2006). Spatial and temporal variability in the concentration and speciation of metals in suspended sediment transported by the River Aire, Yorkshire, UK.
HYDROLOGICAL PROCESSES,
20(14), 3007-3027.
Author URL.
Ballantine D, Walling DE, Leeks GJL (2006). The deposition and storage of sediment-associated phosphorus on the flood plains of two lowland groundwater fed catchments.
Author URL.
Schuller P, Iroume A, Walling DE, Mancilla HB, Castillo A, Trumper RE (2006). Use of beryllium-7 to document soil redistribution following forest harvest operations.
JOURNAL OF ENVIRONMENTAL QUALITY,
35(5), 1756-1763.
Author URL.
2005
Thorndycraft VR, Benito G, Walling DE, Sopena A, Sanchez-Moya Y, Rico M, Casas A (2005). Caesium-137 dating applied to slackwater flood deposits of the Llobregat River, NE Spain.
CATENA,
59(3), 305-318.
Author URL.
Droppo IG, Nackaerts K, Walling DE, Williams N (2005). Can floes and water stable soil aggregates be differentiated within fluvial systems?.
CATENA,
60(1), 1-18.
Author URL.
Walling DE, Zhang X (2005). Characterizing land surface erosion from cesium-137 profiles in lake and reservoir sediments. Journal of Environmental Quality, 34(2), 514-523.
Porto P, Walling DE, Callegari G (2005). Investigating sediment sources within a small catchment in southern Italy.
Author URL.
Collins AL, Walling DE, Leeksz GJL (2005). Storage of fine-grained sediment and associated contaminants within the channels of lowland permeable catchments in the UK.
Author URL.
Walling DE, Collins AL (2005). Suspended sediment sources in British rivers.
Author URL.
Walling DE (2005). Tracing suspended sediment sources in catchments and river systems. Science of the Total Environment, 344(1-3), 159-184.
Haciyakupoglu S, Ertek TA, Walling DE, Ozturk ZF, Karahan G, Erginal AE, Celebi N (2005). Using caesium-137 measurements to investigate soil erosion rates in western Istanbul (NW Turkey).
CATENA,
64(2-3), 222-231.
Author URL.
2004
Piegay H, Walling DE, Landon N, He QP, Liebault F, Petiot R (2004). Contemporary changes in sediment yield in an alpine mountain basin due to afforestation (the upper Drome in France).
Author URL.
Collins AL, Walling DE (2004). Documenting catchment suspended sediment sources: problems, approaches and prospects.
PROGRESS IN PHYSICAL GEOGRAPHY-EARTH AND ENVIRONMENT,
28(2), 159-196.
Author URL.
Wilson AJ, Walling DE, Leeks GJL (2004). In-channel storage of fine sediment in rivers of southwest England.
Author URL.
Sutton RI, Nicholas AP, Walling DE (2004). Monitoring and modelling flow and suspended sediment transport processes in alluvial cutoffs.
Abstract:
Monitoring and modelling flow and suspended sediment transport processes in alluvial cutoffs
Abstract.
Walling DE, Zhang Y (2004). Predicting slope-channel connectivity: a national-scale approach.
Author URL.
Zhang XB, He XB, Wen AB, Walling DE, Feng MY, Zou X (2004). Sediment source identification by using Cs-137 and Pb-210 radionuclides in a small catchment of the Hilly Sichuan Basin, China.
CHINESE SCIENCE BULLETIN,
49(18), 1953-1957.
Author URL.
Walling DE, Fang D, Nicholas AP, Sweet RJ (2004). The grain size characteristics of overbank deposits on the flood plains of British lowland rivers.
Abstract:
The grain size characteristics of overbank deposits on the flood plains of British lowland rivers
Abstract.
Williams ND, Walling DE, Leeks GJL (2004). The settling behaviour of fine sediment particles: some preliminary results from LISST instruments.
Author URL.
Schuller P, Walling DE, Sepulveda A, Trumper RE, Rouanet JL, Pino I, Castillo A (2004). Use of Cs-137 measurements to estimate changes in soil erosion rates associated with changes in soil management practices on cultivated land.
APPLIED RADIATION AND ISOTOPES,
60(5), 759-766.
Author URL.
Walling DE (2004). Using environmental radionuclides to trace sediment mobilisation and delivery in river basins as an aid to catchment management.
Author URL.
Porto P, Walling DE, Callegari G (2004). Validating the use of caesium-137 measurements to estimate erosion rates in three small catchments in Southern Italy.
Author URL.
2003
Walling DE, Collins AL, McMellin GK (2003). A reconnaissance survey of the source of interstitial fine sediment recovered from salmonid spawning gravels in England and Wales.
HYDROBIOLOGIA,
497(1-3), 91-108.
Author URL.
Feng MY, Walling DE, Zhang XB, Wen AB (2003). A study on responses of soil erosion and sediment yield to closing cultivation on sloping land in a small catchment using Cs-137 technique in the Rolling Loess Plateau, China.
CHINESE SCIENCE BULLETIN,
48(19), 2093-2100.
Author URL.
Ritchie JC, Walling DE, Peters J (2003). Application of geographic information systems and remote sensing for quantifying patterns of erosion and water quality. Hydrological Processes, 17(5), 885-886.
Walling DE, Owens PN, Foster IDL, Lees JA (2003). Changes in the fine sediment dynamics of the Ouse and Tweed basins in the UK over the last 100-150 years.
Author URL.
Carter J, Owens PN, Walling DE, Leeks GJL (2003). Fingerprinting suspended sediment sources in a large urban river system.
Abstract:
Fingerprinting suspended sediment sources in a large urban river system.
Abstract.
Author URL.
Sweet RJ, Nicholas AP, Walling DE, Fang X (2003). Morphological controls on medium-term sedimentation rates on British lowland river floodplains.
Abstract:
Morphological controls on medium-term sedimentation rates on British lowland river floodplains
Abstract.
Meharg AA, Wright J, Leeks GJL, Wass PD, Owens PN, Walling DE, Osborn D (2003). PCB congener dynamics in a heavily industrialized river catchment.
Author URL.
Zhang XB, Walling DE, Feng MY, Wen AB (2003). Pb-210(ex) depth distribution in soil and calibration models for assessment of soil erosion rates from Pb-210(ex) measurements.
CHINESE SCIENCE BULLETIN,
48(8), 813-818.
Author URL.
Walling DE, Fang D (2003). Recent trends in the suspended sediment loads of the world's rivers.
GLOBAL AND PLANETARY CHANGE,
39(1-2), 111-126.
Author URL.
Walling DE, Fang D (2003). Recent trends in the suspended sediment loads of the worlds rivers. Global and Planetary Change, 39(1-2), 111-126.
Porto P, Walling DE, Tamburino V, Callegari G (2003). Relating caesium-137 and soil loss from cultivated land.
CATENA,
53(4), 303-326.
Author URL.
Theocharopoulos SP, Florou H, Walling DE, Kalantzakos H, Christou M, Tountas P, Nikolaou T (2003). Soil erosion and deposition rates in a cultivated catchment area in central Greece, estimated using the Cs-137 technique.
SOIL & TILLAGE RESEARCH,
69(1-2), 153-162.
Author URL.
Walling DE, Owens PN, Carter J, Leeks GJL, Lewis S, Meharg AA, Wright J (2003). Storage of sediment-associated nutrients and contaminants in river channel and floodplain systems.
APPLIED GEOCHEMISTRY,
18(2), 195-220.
Author URL.
Heywood MJT, Walling DE (2003). Suspended sediment fluxes in chalk streams in the Hampshire Avon catchment, UK.
Author URL.
Owens PN, Walling DE (2003). Temporal changes in the metal and phosphorus content of suspended sediment transported by Yorkshire rivers, UK over the last 100 years, as recorded by overbank floodplain deposits.
Author URL.
He Q, Walling DE (2003). Testing distributed soil erosion and sediment delivery models using Cs-137 measurements.
HYDROLOGICAL PROCESSES,
17(5), 901-916.
Author URL.
Ankers C, Walling DE, Smith RP (2003). The influence of catchment characteristics on suspended sediment properties.
Author URL.
Walling DE, Owens PN (2003). The role of overbank floodplain sedimentation in catchment contaminant budgets.
Author URL.
Walling DE, Collins AL, Sichingabula HM, Leeks GJL (2003). Use of reconnaissance measurements to establish catchment sediment budgets: a Zambian example.
Author URL.
Walling DE, He Q, Whelan PA (2003). Using (CS)-C-137 measurements to validate the application of the AGNPS and ANSWERS erosion and sediment yield models in two small Devon catchments.
SOIL & TILLAGE RESEARCH,
69(1-2), 27-43.
Author URL.
Walling DE (2003). Using environmental radionuclides as tracers in sediment budget investigations.
Author URL.
Walling DE, Collins AL, Sichingabula HM (2003). Using unsupported lead-210 measurements to investigate soil erosion and sediment delivery in a small Zambian catchment. Geomorphology, 52(3-4), 193-213.
Porto P, Walling DE, Ferro V, Di Stefano C (2003). Validating erosion rate estimates provided by caesium-137 measurements for two small forested catchments in Calabria, southern Italy.
LAND DEGRADATION & DEVELOPMENT,
14(4), 389-408.
Author URL.
Webb BW, Clack PD, Walling DE (2003). Water-air temperature relationships in a Devon river system and the role of flow.
HYDROL PROCESS,
17(15), 3069-3084.
Abstract:
Water-air temperature relationships in a Devon river system and the role of flow
The nature of the water-air temperature relationship, and its moderation by discharge, were investigated for catchments ranging in size from 2.1 to 601 km(2) in the Exe basin, Devon, UK and for data relating to hourly, daily and weekly time bases. The sensitivity and explanatory power of simple water-air temperature regression models based on hourly data were improved by incorporation of a lag, which increased with catchment size, although relationships became more sensitive and less scattered as the time base of data increased from hourly to weekly mean values. Significant departures from linearity in water-air temperature relationships were evident for hourly, but not for daily mean or weekly mean, data. A clear tendency for relationships between water and air temperatures to be stronger and more sensitive for flows below median levels was apparent, and multiple regression analysis also revealed water temperature to be inversely related to discharge for all catchments and time-scales. However, discharge had a greater impact in accounting for water temperature variation at shorter time-scales and in larger catchments. Copyright (C) 2003 John Wiley Sons, Ltd.
Abstract.
2002
Owens PN, Walling DE (2002). Changes in sediment sources and floodplain deposition rates in the catchment of the River Tweed, Scotland, over the last 100 years: the impact of climate and land use change.
EARTH SURFACE PROCESSES AND LANDFORMS,
27(4), 403-423.
Author URL.
Woodward JC, Porter PR, Lowe AT, Walling DE, Evans AJ (2002). Composite suspended sediment particles and flocculation in glacial meltwaters: Preliminary evidence from alpine and himalayan basins.
Hydrological Processes,
16(9), 1735-1744.
Abstract:
Composite suspended sediment particles and flocculation in glacial meltwaters: Preliminary evidence from alpine and himalayan basins
Research over the last decade has shown that the suspended sediment loads of many rivers are dominated by composite particles. These particles are also known as aggregates or flocs, and are commonly made up of constituent mineral particles, which evidence a wide range of grain sizes, and organic matter. The resulting in situ or effective particle size characteristics of fluvial suspended sediment exert a major control on all processes of entrainment, transport and deposition. The significance of composite suspended sediment particles in glacial meltwater streams has, however, not been established. Existing data on the particle size characteristics of suspended sediment in glacial meltwaters relate to the dispersed mineral fraction (absolute particle size), which, for certain size fractions, may bear little relationship to the effective or in situ distribution. Existing understanding of composite particle formation within freshwater environments would suggest that in-stream flocculation processes do not take place in glacial meltwater systems because of the absence of organic binding agents. However, we report preliminary scanning electron microscopy data for one Alpine and two Himalayan glaciers that show composite particles are present in the suspended sediment load of the meltwater system. The genesis and structure of these composite particles and their constituent grain size characteristics are discussed. We present evidence for the existence of both aggregates, or composite particles whose features are largely inherited from source materials, and flocs, which represent composite particles produced by in-stream flocculation processes. In the absence of organic materials, the latter may result solely from electrochemical flocculation in the meltwater sediment system. This type of floc formation has not been reported previously in the freshwater fluvial environment. Further work is needed to test the wider significance of these data and to investigate the effective particle size characteristics of suspended sediment associated with high concentration outburst events. Such events make a major contribution to suspended sediment fluxes in meltwater streams and may provide conditions that are conducive to composite particle formation by flocculation. Copyright © 2002 John Wiley and Sons, Ltd.
Abstract.
Walling DE, Russell MA, Hodgkinson RA, Zhang Y (2002). Establishing sediment budgets for two small lowland agricultural catchments in the UK.
CATENA,
47(4), 323-353.
Author URL.
Collins AL, Walling DE (2002). Selecting fingerprint properties for discriminating potential suspended sediment sources in river basins.
JOURNAL OF HYDROLOGY,
261(1-4), 218-244.
Author URL.
Owens PN, Walling DE (2002). The phosphorus content of fluvial sediment in rural and industrialized river basins.
Water Res,
36(3), 685-701.
Abstract:
The phosphorus content of fluvial sediment in rural and industrialized river basins.
The phosphorus content of fluvial sediment (suspended sediment and the < 63 microm fraction of floodplain and channel bed sediment) has been examined in contrasting rural (moorland and agricultural) and industrialized catchments in Yorkshire, UK. The River Swale drains a rural catchment with no major urban and industrial areas, and the total phosphorus (TP) content of fluvial sediment is generally within the range 500-1,500 microg g(-1). There is little evidence of any major downstream increase in TP content. In contrast, fluvial sediment from the industrialized catchments of the Rivers Aire and Calder exhibits both higher levels of TP content and marked downstream increases, with values of TP content ranging from < 2,000 microg g(-1) in headwater areas upstream of the main urban and industrial areas, to values > 7,000 microg g(-1) at downstream sites. These elevated levels reflect P inputs from point sources, such as sewage treatment works (STWs) and combined sewer overflows. The influence of STWs is further demonstrated by the downstream increase in the inorganic P/organic P ratio from < 2 in the headwaters to > 4 in the lower reaches. Comparison of the P content of suspended sediment with that of the
Abstract.
Author URL.
Walling DE, Owens PN (2002). The role of flood plain sedimentation in catchment sediment and contaminant budgets.
Author URL.
Blake WH, Walling DE, He Q (2002). Using cosmogenic beryllium-7 as a tracer in sediment budget investigations.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
84A(2), 89-102.
Author URL.
2001
Walling DE, Russell, Webb BW (2001). Controls on the nutrient content of suspended sediment transported by British rivers.
Abstract:
Controls on the nutrient content of suspended sediment transported by British rivers.
Abstract.
Author URL.
Owens PN, Walling DE, Carton J, Meharg AA, Wright J, Leeks GJ (2001). Downstream changes in the transport and storage of sediment-associated contaminants (P, Cr and PCBs) in agricultural and industrialized drainage basins.
Abstract:
Downstream changes in the transport and storage of sediment-associated contaminants (P, Cr and PCBs) in agricultural and industrialized drainage basins.
Abstract.
Author URL.
Walling DE, Collins AL, Sichingabula HM, Leeks GJL (2001). Integrated assessment of catchment suspended sediment budgets: a Zambian example.
LAND DEGRADATION & DEVELOPMENT,
12(5), 387-415.
Author URL.
Collins AL, Walling DE, Sichingabula HM, Leeks GJL (2001). Suspended sediment source fingerprinting in a small tropical catchment and some management implications.
APPLIED GEOGRAPHY,
21(4), 387-412.
Author URL.
Russell MA, Walling DE, Hodgkinson RA (2001). Suspended sediment sources in two small lowland agricultural catchments in the UK.
JOURNAL OF HYDROLOGY,
252(1-4), 1-24.
Author URL.
Panin AV, Walling DE, Golosov VN (2001). The role of soil erosion and fluvial processes in the post-fallout redistribution of Chernobyl-derived caesium-137: a case study of the Lapki catchment, Central Russia.
GEOMORPHOLOGY,
40(3-4), 185-204.
Author URL.
Collins AL, Walling DE, Sichingabula HM, Leeks GJL (2001). Using (CS)-C-137 measurements to quantify soil erosion and redistribution rates for areas under different land use in the Upper Kaleya River basin, southern Zambia.
GEODERMA,
104(3-4), 299-323.
Author URL.
Porto P, Walling DE, Ferro V (2001). Validating the use of caesium-137 measurements to estimate soil erosion rates in a small drainage basin in Calabria, Southern Italy.
JOURNAL OF HYDROLOGY,
248(1-4), 93-108.
Author URL.
2000
Webb BW, Phillips JM, Walling DE (2000). A new approach to deriving 'best-estimate' chemical fluxes for rivers draining the LOIS study area.
Sci Total Environ,
251-252, 45-54.
Abstract:
A new approach to deriving 'best-estimate' chemical fluxes for rivers draining the LOIS study area
A central objective of the LOIS Community Research Programme was to provide estimates of the land-ocean flux of chemical species from the LOIS study area. In the absence of detailed information on the concentration of most of the dissolved and particulate-associated chemical constituents, it has proved necessary to make use of the relatively infrequent samples collected in the UK Harmonised Monitoring Scheme, in order to estimate chemical fluxes for the LOIS rivers. In these circumstances, standard procedures may provide unreliable results, and a new approach has been developed to derive improved estimates of chemical flux from the LOIS study area. This approach is based on the generation of detailed synthetic time series of concentration, which are used to estimate the likely errors associated with different flux calculation procedures, especially those resulting from differences in the timing of chemographs and hydrographs during storm events. The approach was applied on a river by river and determinand by determinand basis to identify and to employ the best methods for computing fluxes of 45 chemical determinands from the LOIS study area during the period 1992-1996.
Abstract.
Author URL.
Golosov VN, Walling DE, Kvasnikova EV, Stukin ED, Nikolaev AN, Panin AV (2000). Application of a field-portable scintillation detector for studying the distribution of Cs-137 inventories in a small basin in Central Russia.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY,
48(1), 79-94.
Author URL.
Russell MA, Walling DE, Hodgkinson RA (2000). Appraisal of a simple sampling device for collecting time-integrated fluvial suspended sediment samples.
Author URL.
He Q, Walling DE (2000). Calibration of a field-portable gamma detector to obtain in situ measurements of the 137Cs inventories of cultivated soils and floodplain sediments.
Appl Radiat Isot,
52(4), 865-872.
Abstract:
Calibration of a field-portable gamma detector to obtain in situ measurements of the 137Cs inventories of cultivated soils and floodplain sediments.
Over the past 10 years, a number of studies have exploited the potential for using measurements of fallout 137Cs inventories to document rates and patterns of soil erosion on cultivated land and to estimate rates of overbank sedimentation on river floodplains. Traditional procedures for applying the 137Cs technique involve the collection of soil or sediment cores from a study site and their subsequent transfer to the laboratory for preparation and analysis by gamma spectrometry. Such procedures are time consuming and there may be a considerable delay before the results are available. It is therefore difficult to obtain preliminary results, which could be used to guide the development of an ongoing sampling programme. The use of in situ gamma spectrometry measurements to quantify 137Cs inventories in soils and sediments offers a number of potential advantages over traditional procedures. However, in order to derive a reliable estimate of the 137Cs inventory for a measurement point, it is necessary to take account of the attenuation of 137Cs gamma rays by the soil matrix and information on the depth distribution of 137Cs in the soil or sediment is therefore required. In the present study, empirical relationships between in situ measurements of 137Cs activity and total 137Cs inventories have been established for soils from a cultivated field and for floodplain sediments, based on information on the vertical distribution of 137Cs in the soils and sediments provided by the forward scattering ratio derived from the field measured spectra. These relationships have been used to estimate 137Cs inventories from in situ measurements of 137Cs activity at other locations.
Abstract.
Author URL.
Walling DE, Woodward JC (2000). Effective particle size characteristics of fluvial suspended sediment transported by lowland British rivers.
Author URL.
Foster IDL, Mighall TM, Wotton C, Owens PN, Walling DE (2000). Evidence for Mediaeval soil erosion in the South Hams region of Devon, UK.
HOLOCENE,
10(2), 261-271.
Author URL.
Walling DE, Golosov VN, Kvasnikova EV, Vandecasteele C (2000). Radioecological aspects of soil pollution in small catchments.
EURASIAN SOIL SCIENCE,
33(7), 776-784.
Author URL.
Walling DE, He Q, Blake WH (2000). River flood plains as phosphorus sinks.
Author URL.
Hasholt B, Walling DE, Owens PN (2000). Sedimentation in arctic proglacial lakes: Mittivakkat Glacier, south-east Greenland.
HYDROLOGICAL PROCESSES,
14(4), 679-699.
Author URL.
Carton J, Walling DE, Owens PN, Leeks GJL (2000). Spatial and temporal variability of the chromium content of suspended and flood-plain sediment in the River Aire, Yorkshire, UK.
Author URL.
Walling DE, Owens PN, Waterfall BD, Leeks GJ, Wass PD (2000). The particle size characteristics of fluvial suspended sediment in the Humber and Tweed catchments, UK.
Sci Total Environ,
251-252, 205-222.
Abstract:
The particle size characteristics of fluvial suspended sediment in the Humber and Tweed catchments, UK
This paper presents information on the absolute (chemically-dispersed) particle size characteristics of the suspended sediment transported by rivers in the Humber and Tweed basins during the period 1994-1998. For most of the rivers, > 95% of the suspended sediment load at the time of sampling was < 63 microm (i.e. silt- and clay-sized material) and < 5% was > 63 microm (i.e. sand-sized material). The < 2 microm fraction (i.e. clay-sized material) typically ranged between 15 and 25%. The average median (d50) particle size for the individual rivers ranged between 4.1 and 13.5 microm. Generally, the particle size characteristics of suspended sediment transported in the two basins were similar. There were, however, noticeable spatial variations in the particle size composition of suspended sediment within the study basins, which reflected the particle size of the sediment sources and their spatial variation, and the selectivity of the sediment mobilization and delivery processes. When particle size parameters were plotted against discharge, there were no significant relationships, although there was some evidence of trends varying between sites. The lack of significant relationships with discharge reflects the fact that sediment particle size is largely supply-controlled, rather than a function of flow and hydraulics. When particle size variations were examined during individual storm events, there was evidence of a pulse of coarse sediment on the rising limb of the hydrograph. This may reflect the remobilization of coarse channel bed sediment as flow velocity and shear stress increase. Finer sediment was transported subsequently during the hydrograph peak and on the falling limb. The findings reported have important implications for understanding and modelling suspended sediment, and associated contaminant, dynamics in river basins.
Abstract.
Author URL.
Phillips JM, Russell MA, Walling DE (2000). Time-integrated sampling of fluvial suspended sediment: a simple methodology for small catchments.
HYDROLOGICAL PROCESSES,
14(14), 2589-2602.
Author URL.
Owens PN, Walling DE, Leeks GJL (2000). Tracing fluvial suspended sediment sources in the catchment of the River Tweed, Scotland, using composite fingerprints and a numerical mixing model.
Author URL.
Walling DE, Golosov VN, Panin AV, He Q (2000). Use of radiocaesium to investigate erosion and sedimentation in areas with high levels of Chernobyl fallout.
Author URL.
Bottrill LJ, Walling DE, Leeks GJL (2000). Using recent overbank deposits to investigate contemporary sediment sources in larger river basins.
Author URL.
1999
Siggers GB, Bates PD, Anderson MG, Walling DE, He Q (1999). A preliminary investigation of the integration of modelled floodplain hydraulics with estimates of overbank floodplain sedimentation derived from Pb-210 and Cs-137 measurements.
EARTH SURFACE PROCESSES AND LANDFORMS,
24(3), 211-231.
Author URL.
Walling DE, He Q (1999). Changing rates of overbank sedimentation on the floodplains of British rivers during the past 100 years.
Author URL.
Owens PN, Walling DE, Leeks GJL (1999). Deposition and storage of fine-grained sediment within the main channel system of the River Tweed, Scotland.
Author URL.
Phillips JM, Webb BW, Walling DE, Leeks GJL (1999). Estimating the suspended sediment loads of rivers in the LOIS study area using infrequent samples.
HYDROL PROCESS,
13(7), 1035-1050.
Abstract:
Estimating the suspended sediment loads of rivers in the LOIS study area using infrequent samples
A central objective of the LOIS Community Research Programme is to provide estimates of the land-ocean flux of suspended sediment from the LOIS study area. While high frequency (15-minute interval) suspended sediment concentration data are recorded within the programme at six tidal limit sites, infrequent (weekly-monthly) sampling undertaken by the Harmonized Monitoring (HM) Programme provides additional concentration data for 23 tidal limit sites in the LOIS study area. In order that these infrequent data can be used to generate sediment flux estimates, the accuracy and precision of 22 load estimation procedures are assessed in the context of sampling frequency (weekly, fortnightly and monthly) and basin scales representative of the LOIS study area. Sampling frequency is demonstrated to exert a significant influence on the precision of the individual procedures, with precision being inversely related to sampling frequency. Accuracy is less clearly influenced by sampling frequency, although different procedures were identified as being the most accurate at the three sampling frequencies. Basin scale is shown to exert a significant influence upon accuracy and precision, with the performance of the load estimation procedures being inversely related to basin scale. For one interpolation procedure, an error correction procedure is developed, based on the strong relationship identified in this study between the error associated with individual flux estimates and the ratio of mean sampled discharge to the mean discharge obtained from the high frequency record. This relatively high resolution error correction method is applied to HM data from eight tidal limit sites in the LOIS area, and corrects the initial annual load estimates to provide values that are considered to be more representative of rivers from the LOIS study area. Copyright (C) 1999 John Wiley & Sons, Ltd.
Abstract.
Blake WH, Walling DE, He Q (1999). Fallout beryllium-7 as a tracer in soil erosion investigations.
Appl Radiat Isot,
51(5), 599-605.
Abstract:
Fallout beryllium-7 as a tracer in soil erosion investigations.
Recent developments in the use of the environmental radionuclides 137Cs and 210Pb for documenting medium-term soil erosion rates must be seen as an important advance. However, measurements of these radionuclides provide estimates of medium-term (i.e. ca. 45 or 100 years) soil redistribution rates and there is a need to explore the potential for using complementary radionuclides, to estimate erosion rates associated with individual events or short periods. Beryllium-7 (7Be, t0.5 = 53 days) has the potential to fulfil these requirements. This contribution presents some preliminary results from an investigation undertaken in a field near Crediton, UK, which successfully demonstrates the potential for using 7Be as a tracer in soil erosion investigations.
Abstract.
Author URL.
Walling DE, Owens PN, Leeks GJL (1999). Fingerprinting suspended sediment sources in the catchment of the River Ouse, Yorkshire, UK.
HYDROLOGICAL PROCESSES,
13(7), 955-975.
Author URL.
Bottrill LJ, Walling DE, Leeks GJ (1999). Geochemical characteristics of overbank deposits and their potential for determining suspended sediment provenance; an example from the River Severn, UK.
Author URL.
Walling DE, He Q (1999). Improved models for estimating soil erosion rates from cesium-137 measurements.
Author URL.
Walling DE (1999). Invited lecture: River floodplains as sediment sinks.
Author URL.
Walling DE (1999). Linking land use, erosion and sediment yields in river basins.
Author URL.
Walling DE (1999). Linking land use, erosion and sediment yields in river basins.
HYDROBIOLOGIA,
410, 223-240.
Abstract:
Linking land use, erosion and sediment yields in river basins
Results obtained from erosion plots and catchment experiments provide clear evidence of the sensitivity of erosion rates to land use change and related human activity. Evidence for the impact of land use on the sediment yields of world rivers is less clear, although examples of rivers where sediment yields have both increased and decreased in recent decades can be identified. The apparent lack of sensitivity of river sediment loads to land use change reflects, at least in part, the buffering capacity associated with many river basins. This buffering capacity is closely related to the sediment delivery ratio of a river basin, in that basins with high sediment delivery ratios are likely to exhibit a reduced buffering capacity. Investigations of the impact of land use and related human activity on sediment yields should consider the overall sediment budget of a catchment rather than simply the sediment output. Information on the sediment budget of a drainage basin is difficult to assemble using traditional techniques, but recent developments in the application of fingerprinting techniques to establish sediment sources and in the use of environmental radionuclides, such as caesium-137 and lead-210, to document sediment storage offer considerable potential for providing such information. Sediment storage within a river basin can give rise to environmental problems where sediment-associated pollutants accumulate in sediment sinks. The accumulation of phosphorus on river floodplains as a result of overbank sedimentation can, for example, represent an important phosphorus sink.
Abstract.
Quine TA, Walling DE, Chakela QK, Mandiringana OT, Zhang X (1999). Rates and patterns of tillage and water erosion on terraces and contour strips: Evidence from caesium-137 measurements.
Catena,
36(1-2), 115-142.
Abstract:
Rates and patterns of tillage and water erosion on terraces and contour strips: Evidence from caesium-137 measurements
Despite the widespread use of contour-strips and terraces for soil conservation little is known concerning the impact of such measures on rates and patterns of tillage erosion and tillage translocation. Caesium-137 (137Cs) measurements would appear to offer a rapid means of assembling data relevant to the evaluation of tillage erosion and tillage translocation. However, use of 137Cs data in this way requires an approach to the analysis of 137Cs data which accounts for both tillage erosion and tillage translocation. The latter is particularly significant on short slopes. A method of analysing 137Cs data has been developed, that employs a linear, multistore, mass-balance model of soil and 137Cs redistribution to permit estimation of the contributions to erosion from both water and tillage erosion. This method is outlined and results from its application are discussed using case studies from Yanting, in Sichuan Province, China; Ha Sofonia, in Lesotho; and, Chinamora, in Zimbabwe. These case studies confirm the viability of the approach and provide valuable evidence for the importance of tillage erosion and translocation on terraces and contour-strips subject to cultivation by animal traction. Gross rates of tillage erosion were found to be of comparable or greater magnitude than gross rates of water erosion on the fields examined. It is, therefore, suggested that any evaluation of on-site impacts of erosion must take account of tillage erosion. Relationships between annual soil fluxes due to tillage and slope tangent were found to be very similar to the relationships established for a single pass of equivalent tillage equipment with mechanical traction. Furthermore, because tillage by animal traction necessitates downslope turning of the soil on every occasion, net downslope fluxes of soil associated with animal traction may exceed the levels associated with tillage by mechanised traction, in which the soil is typically turned in opposing directions on successive occasions.
Abstract.
Walling DE, Owens PN, Leeks GJL (1999). Rates of contemporary overbank sedimentation and sediment storage on the floodplains of the main channel systems of the Yorkshire Ouse and River Tweed, UK.
HYDROLOGICAL PROCESSES,
13(7), 993-1009.
Author URL.
Leeks GJL, Walling DE (1999). River basin sediment dynamics and interactions within the UK Land-Ocean Interaction Study: the context.
HYDROLOGICAL PROCESSES,
13(7), 931-934.
Author URL.
Walling DE, Amos CM (1999). Source, storage and mobilisation of fine sediment in a chalk stream system.
HYDROLOGICAL PROCESSES,
13(3), 323-340.
Author URL.
Phillips JM, Walling DE (1999). The particle size characteristics of fine-grained channel deposits in the River Exe Basin, Devon, UK.
HYDROLOGICAL PROCESSES,
13(1), 1-19.
Author URL.
Golosov VN, Walling DE, Panin AV, Stukin ED, Kvasnikova EV, Ivanova NN (1999). The spatial variability of Chernobyl-derived Cs-137 inventories in a small agricultural drainage basin in central Russia.
APPLIED RADIATION AND ISOTOPES,
51(3), 341-352.
Author URL.
Quine TA, Walling DE, Zhang X (1999). Tillage erosion, water erosion and soil quality on cultivated terraces near Xifeng in the Loess Plateau, China.
Land Degradation and Development,
10(3), 251-274.
Abstract:
Tillage erosion, water erosion and soil quality on cultivated terraces near Xifeng in the Loess Plateau, China
This study sought to contribute to the understanding of soil redistribution by tillage on terraces and the extent and causes of within-field variation in soil properties by examining the spatial distributions of soil redistribution rates, derived using caesium-137, and of total nitrogen and total phosphorus concentrations, within a ribbon and a shoulder terrace in a yuan area of the Loess Plateau of China. Additional water erosion rate data were obtained for nine other terraces. Water erosion rates on the ribbon terraces were low (
Abstract.
Walling DE, He Q, Blake W (1999). Use of Be-7 and Cs-137 measurements to document short- and medium-term rates of water-induced soil erosion on agricultural land.
WATER RESOURCES RESEARCH,
35(12), 3865-3874.
Author URL.
Owens PN, Walling DE, Leeks GJL (1999). Use of floodplain sediment cores to investigate recent historical changes in overbank sedimentation rates and sediment sources in the catchment of the River Ouse, Yorkshire, UK.
CATENA,
36(1-2), 21-47.
Author URL.
Walling DE, He Q (1999). Using fallout lead-210 measurements to estimate soil erosion on cultivated land.
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL,
63(5), 1404-1412.
Author URL.
Walling DE (1999). Using fallout radionuclides in investigations of contemporary overbank sedimentation on the floodplains of British rivers.
Author URL.
1998
He Q, Walling DE (1998). An investigation of the spatial variability of the grain size composition of floodplain sediments.
HYDROLOGICAL PROCESSES,
12(7), 1079-1094.
Author URL.
King BP, Quine TA, Walling DE, SEDIMENTAT INTRESTCTRE, SEDIMENTAT INTRESTCTRE (1998). Assessment of within-field sediment storage in agricultural catchments using a terrain-based GIS.
Author URL.
Phillips JM, Walling DE (1998). Calibration of a Par-Tec 200 laser back-scatter probe for in situ sizing of fluvial suspended sediment.
HYDROLOGICAL PROCESSES,
12(2), 221-231.
Author URL.
Foster IDL, Lees JA, Owens PN, Walling DE (1998). Mineral magnetic characterization of sediment sources from an analysis of lake and floodplain sediments in the catchments of the Old Mill Reservoir and Slapton Ley, South Devon, UK.
EARTH SURFACE PROCESSES AND LANDFORMS,
23(8), 685-703.
Author URL.
Nicholas AP, Walling DE (1998). Numerical modelling of floodplain hydraulics and suspended sediment transport and deposition.
Hydrological Processes,
12(8), 1339-1355.
Abstract:
Numerical modelling of floodplain hydraulics and suspended sediment transport and deposition
A numerical model is presented for the prediction of floodplain inundation extents, flow depths and velocities, and patterns of suspended sediment dispersion and deposition. The model employs a simplified and novel treatment of fluid flow and a conventional convection-diffusion mass balance relationship for suspended sediment transport and deposition. These relationships are solved over a finite difference grid with a relatively fine nodal spacing, which enables a detailed representation of complex floodplain topography. The model is applied to a 600 m reach of the River Culm, Devon, UK. Continuous records of river stage and susepnded sediment concentration monitored at the upstream boundary of the study reach provide the data needed to operate the model. These data are supplemented by measurements of the in situ settling characteristics of the suspended sediment load. Model predictions of overbank flow depths and velocities and patterns of suspended sediment concentrations and deposition amounts are presented. Predicted patterns of overbank deposition are described and compared with field measurements obtained with the aid of astroturf sedimentation traps are also examined and compared with model predictions. The results of both the field measurement programme and modelling work are shown to have significant implications for the representation of floodplain topography and suspended sediment particle size and settling properties in numerical simulations of overbank processes.
Abstract.
Walling DE, SEDIMENTAT INTRESTCTRE, SEDIMENTAT INTRESTCTRE (1998). Opportunities for using environmental radionuclides in the study of watershed sediment budgets.
Author URL.
Zhang X, Quine TA, Walling DE (1998). Soil erosion rates on sloping cultivated land on the Loess Plateau near Ansai, Shaanxi Province, China: an investigation using <sup>137</sup>Cs and rill measurements.
Hydrological Processes,
12(1), 171-189.
Abstract:
Soil erosion rates on sloping cultivated land on the Loess Plateau near Ansai, Shaanxi Province, China: an investigation using 137Cs and rill measurements
Sediment yields from the rolling hills area of the Loess Plateau in northern China (10 000-25 000 t km-2 yr-1) are amongst the highest in the world. The sediment is believed to derive from both the deep gullies that dissect the rolling plateau and the steep cultivated fields on the slopes of the mounds between the gullies. However, there are few reliable data for erosion rates on the cultivated fields and it is suspected that current estimates (10 000-16 000 t km-2 yr-1) based on empirical relationships (derived from erosion plot studies) exceed the true values. This study sought to address the need for more information concerning erosion of the cultivated fields through derivation of erosion rates from measurements of rill volume and caesium-137 (137Cs) inventories for typical fields near the village of Ansai, Shaanxi Province. The derived erosion rates are discussed and compared with estimates based on empirical relationships derived from erosion plot data. Where erosion rate estimates based on both rill volume data and 137Cs inventories are available, they show good agreement in the pattern of downslope variation. Both show a sharp decline in erosion rates at a slope length of c. 50 m. This is tentatively attributed to a change from transport-limited to detachment-limited conditions, where rill incision reaches the undisturbed loess at the base of the plough layer. No such decline is visible in the predictions based on empirical relationships derived from erosion plot data. Further evidence is presented that supports the suggestion that these empirical relationships overestimate erosion rates at slope lengths in excess of c. 50 m. It is tentatively suggested that the rates of soil erosion from sloping cultivated fields in the rolling hills area are more likely to lie in the range 8000-10000 t km-2 yr-1 than in the higher range suggested by the empirical relationships. © 1998 John Wiley Sons, Ltd.
Abstract.
Walling DE, Owens PN, Leeks GJL (1998). The characteristics of overbank deposits associated with a major flood event in the catchment of the River Ouse, Yorkshire, UK (vol 31, pg 53, 1997).
CATENA,
32(3-4), 309-331.
Author URL.
Russell MA, Walling DE, Webb BW, Bearne R (1998). The composition of nutrient fluxes from contrasting UK river basins.
HYDROL PROCESS,
12(9), 1461-1482.
Abstract:
The composition of nutrient fluxes from contrasting UK river basins
Accurate estimates of N and P loads were obtained for four contrasting UK river basins over a complete annual cycle. The fractionation of these loads into dissolved and particulate, and inorganic and organic components allowed a detailed examination of the nutrient load composition and of the factors influencing both the relative and absolute magnitude of these components. The particulate phosphorus (TPP) loads account for 26-75% of the annual total phosphorus (TP) transport and are predominantly inorganic. The inorganic (PIP) and organic (POP) fractions of the TPP loads represent 20-47% and 6-28% of the annual TP transport, respectively. In contrast, the particulate nitrogen loads (TPN) represent 8% or less of the annual total nitrogen (TN) loads and are predominately organic. For dissolved P transport, the dissolved inorganic fraction (DIP) is more important, representing 15-70% of the TP loads, whereas the dissolved organic fraction (DOP) represents only 3-9% of the TP loads. The TN loads are dominated by the dissolved component and more particularly the total oxidized fraction (TON), which is composed of nitrate and nitrite and represents 76-82% of the annual TN transport. The remaining dissolved N species, ammonium (NH4-N) and organic N (DON) account for 03-12% and 13-16% of the annual TN transport, respectively. The TPN and TPP fluxes closely reflect the suspended sediment dynamics of the study basins, which are in turn controlled by basin size and morphology. The dissolved inorganic nutrient fluxes are influenced by point source inputs to the study basins, especially for P, although the TON flux is primarily influenced by diffuse source contributions and the hydrological connectivity between the river and its catchment area. The dissolved organic fractions are closely related to the dissolved organic carbon (DOC) dynamics, which are in turn influenced by land use and basin size. The magnitude of the NH4-N fraction was dependent on the proximity of the monitoring station to point source discharges, because of rapid nitrification within the water column. However, during storm events, desorption from suspended sediment may be temporarily important. Both the magnitude and relative contribution of the different nutrient fractions exhibit significant seasonal variability in response to the hydrological regime, sediment mobilization, the degree of dilution of point source inputs and biological processes. (C) 1998 John Wiley & Sons, Ltd.
Abstract.
Walling DE, Owens PN, Leeks GJL (1998). The role of channel and floodplain storage in the suspended sediment budget of the River Ouse, Yorkshire, UK.
GEOMORPHOLOGY,
22(3-4), 225-242.
Author URL.
Walling DE, He Q (1998). The spatial variability of overbank sedimentation on river floodplains.
GEOMORPHOLOGY,
24(2-3), 209-223.
Author URL.
Owens PN, Walling DE (1998). The use of a numerical mass-balance model to estimate rates of soil redistribution on uncultivated land from Cs-137 measurements.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY,
40(2), 185-203.
Author URL.
Collins AL, Walling DE, Leeks GJL (1998). Use of composite fingerprints to determine the provenance of the contemporary suspended sediment load transported by rivers.
EARTH SURFACE PROCESSES AND LANDFORMS,
23(1), 31-52.
Author URL.
Walling DE, He Q (1998). Use of fallout Cs-137 measurements for validating and calibrating soil erosion and sediment delivery models.
Author URL.
1997
Webb BW, Walling DE (1997). Complex summer water temperature behaviour below a UK regulating reservoir.
REGUL RIVER,
13(5), 463-477.
Abstract:
Complex summer water temperature behaviour below a UK regulating reservoir
Detailed monitoring over a 15-year period has revealed considerable complexity in summer water temperature behaviour below Wimbleball Lake, a large regulating reservoir in south-west England. Continuous records of water temperature in the regulated River Haddeo and the neighbouring unregulated River Pulham, coupled with information on flow in the tailbay of the dam and on the thermal structure of the impounded water body, reveal that the nature and extent of the thermal modification below the reservoir varies from day to day, month to month and year to year. This complexity largely reflects changes in the balance between a springflow and a direct reservoir release component of the compensation runoff, which arise in response to variations within and between summers in hydrometeorological conditions and in the way the reservoir is operated to regulate downstream flows. Temperature behaviour in the regulated river is made more complicated by progressive warming of the springflow during the summer months, the thermal inertia of the stored water, the development of thermal stratification within the reservoir and the alteration of release depth. although the detailed effect of some of these factors depends on weather conditions, the use of destratification equipment and the rapidity of reservoir drawdown. (C) 1997 John Wiley & Sons, Ltd.
Abstract.
Quine TA, Govers G, Walling DE, Zhang X, Desmet PJJ, Zhang Y, Vandaele K (1997). Erosion processes and landform evolution on agricultural land - New perspectives from caesium-137 measurements and topographic-based erosion modelling.
Earth Surface Processes and Landforms,
22(9), 799-816.
Abstract:
Erosion processes and landform evolution on agricultural land - New perspectives from caesium-137 measurements and topographic-based erosion modelling
Despite growing interest in soil erosion on agricultural land, relatively little attention has been paid to the influence of erosion processes on the pattern of contemporary landform evolution. This in part reflects the problems associated with up-scaling the results of short-term process studies to temporal and spatial scales relevant to the study of landform evolution. This paper presents a new approach to examining the influence of erosion processes on landform evolution on agricultural land which employs: caesium-137 (137Cs) measurements to provide medium-term (c.40 years) estimates of rates of landform change; experimental data and a topographic-based model to simulate soil redistribution by tillage; a mass-balance model of 137Cs redistribution to separate the water erosion and tillage components of the 137Cs 'signatures'; and field observations of water erosion for validation. This approach is used to examine the relative importance of water erosion and tillage processes for contemporary landform evolution at contrasting sites near Leuven, in Belgium, and near Yanan, in Shaanxi Province, China. This application of the approach provides good agreement between the derived water erosion rates and field observations, and hitherto unobtainable insights into medium-term patterns and rates of contemporary landform evolution. At Huldenberg in Belgium, despite rill incision of slope concavities and ephemeral gully incision of the valley floor, contemporary landform evolution is dominated by infilling of slope and valley concavities (rates >0·5 mm a-1) and gradual lowering of slope angles as a result of tillage. In contrast, at Ansai (near Yanan) the slope is characterized by increase in slope angle over most of the length, recession of the steepest section at a rate >5mm a-1 and by increasing planform curvature. At this site, contemporary landform evolution is dominated by water erosion. The constraints on the approach are examined, with particular attention being given to limitations on extrapolation of the results and to the sensitivity of the models to parameter variation. © 1997 by John Wiley & Sons, Ltd.
Abstract.
Collins AL, Walling DE, Leeks GJL (1997). Fingerprinting the origin of fluvial suspended sediment in larger river basins: Combining assessment of spatial provenance and source type.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
79A(4), 239-254.
Author URL.
Nicholas AP, Walling DE (1997). Investigating spatial patterns of medium-term overbank sedimentation on floodplains: a combined numerical modelling and radiocaesium-based approach.
Geomorphology,
19(1-2), 133-150.
Abstract:
Investigating spatial patterns of medium-term overbank sedimentation on floodplains: a combined numerical modelling and radiocaesium-based approach
A numerical model of overbank deposition of fine-grained suspended sediment is presented and employed to predict spatial patterns of mean annual floodplain sedimentation within a small reach of the River Culm, Devon, UK. The model incorporates a deposition function which is calibrated with the aid of a dataset of measured deposition amounts obtained from nine flood events over a 13 month period. Model predictions of mean annual deposition rates are then compared against an independent dataset comprising estimates of longer-term (ca. 35 years) average sedimentation rates derived from caesium-137 measurements on 200 floodplain sediment cores collected from two floodplain locations. The numerical model is found to adequately reproduce the spatial patterns of overbank sedimentation documented by the 137Cs data. However, where maximum rates of deposition occur, the model is found to seriously underpredict the 137Cs derived estimates. The simulation model employed here might be improved upon by incorporating more sophisticated 2D or 3D numerical treatments of flow hydraulics and suspended sediment transport and settling processes. Such numerical schemes may offer the potential to provide not only more accurate predictions of sedimentation rates, but also more realistic representations of overbank processes. While models of this type are now becoming more widely available, in order for the benefits associated with increased model complexity to be realised, in future, greater emphasis must be placed upon testing models against distributed datasets of hydraulic and sedimentological variables obtained through intensive field monitoring programmes. The use of Cs measurements appears to offer considerable potential in this respect.
Abstract.
Walling DE, He Q (1997). Investigating spatial patterns of overbank sedimentation on river floodplains.
Author URL.
Webb BW, Phillips JM, Walling DE, Littlewood IG, Watts CD, Leeks GJL (1997). Load estimation methodologies for British rivers and their relevance to the LOIS RACS(R) programme.
SCI TOTAL ENVIRON,
194, 379-389.
Abstract:
Load estimation methodologies for British rivers and their relevance to the LOIS RACS(R) programme
Data collected from rivers within the LOIS study area have been analysed to test the reliability of commonly-used interpolation and extrapolation methods for estimating loads from the concentration and flow records that are typically available for rivers in Eastern England. Detailed time series of suspended sediment concentration and discharge, which were collected by means of turbidity monitoring and ultrasonic flow gauging on the River Wharfe at Tadcaster over a 6-month period, have been used to compute a reference load. These data were then artificially decimated to evaluate different procedures for calculating suspended sediment loads. None of the methods investigated produced very reliable load estimates when weekly suspended sediment concentration data were used, and replicate estimates ranged from 24.4 to 550.1% of the reference load. Extrapolation by means of a simple rating relationship was found to produce estimates of suspended sediment load with the highest level of accuracy and precision, but loads calculated by this procedure still varied from -57.2% to +9.1% of the true value at the 95% level of confidence. Reduction in sampling frequency from weekly to fortnightly or monthly intervals generally caused a greater underestimation and increased imprecision in the suspended sediment load estimates. The effect of applying different calculation procedures to estimate chemical fluxes was evaluated using information from the Harmonized Monitoring database for the River Derwent at Church Wilne. For 20 out of the 36 determinands investigated, the difference between the minimum and maximum load estimate, expressed as a percentage of the minimum value, exceeded 50%, and for five determinands, including arsenic in both dissolved and particulate form, the difference was 100% or more. The results of this preliminary analysis suggest that considerable caution should be exercised in calculating river fluxes to the LOIS study coastline, and underscore the need for new and improved procedures to be developed. (C) 1997 Elsevier Science B.V.
Abstract.
Nicholas AP, Walling DE (1997). Modelling flood hydraulics and overbank deposition on river floodplains.
Earth Surface Processes and Landforms,
22(1), 59-77.
Abstract:
Modelling flood hydraulics and overbank deposition on river floodplains
This paper outlines a numerical model for the prediction of floodplain inundation sequences, overbank deposition rates and deposit grain size distributions. The model has two main components: first, a simplified hydraulic scheme which predicts floodwater flow depths and velocities, and second, a sediment transport element which employs a mass balance relation describing suspended sediment dispersion by connective and diffusive processes and sediment deposition as a function of particle settling rates. These relationships are solved numerically on a finite difference grid that accurately replicates the complex topographic features typical of natural river floodplains. The model is applied to a 600 m reach of the River Culm, Devon, U.K. using data derived from a range of field and laboratory techniques. Continuous records of river stage and suspended sediment concentration provide the models upstream boundary input requirements. These are supplemented by measurements of the in situ settling characteristics of the suspended sediment load. The models sediment transport component is calibrated with the aid of a dataset of measured overbank deposition amounts derived from flood events over a 16 month period. The model is shown to predict complicated flood water inundation sequences and patterns of suspended sediment dispersion and deposition, which are largely a product of the complex topography of the floodplain. These results compare favourably with observations of overbank processes and are an improvement over those of previous models which have employed relatively simple representations of floodplain geometry. © 1997 by John Wiley & Sons, Ltd.
Abstract.
Stone PM, Walling DE (1997). Particle size selectivity considerations in suspended sediment budget investigations.
Author URL.
Wilkinson WB, Leeks GJL, Morris A, Walling DE (1997). Rivers and coastal research in the Land Ocean Interaction Study.
SCIENCE OF THE TOTAL ENVIRONMENT,
194, 5-14.
Author URL.
Walling DE, Webb BW, Russell MA (1997). Sediment-associated nutrient transport in UK rivers.
Author URL.
Collins AL, Walling DE, Leeks GJL (1997). Source type ascription for fluvial suspended sediment based on a quantitative composite fingerprinting technique.
CATENA,
29(1), 1-27.
Author URL.
He Q, Walling DE (1997). Spatial variability of the particle size composition of overbank floodplain deposits.
Author URL.
Walling DE, Owens PN, Leeks GJL (1997). The characteristics of overbank deposits associated with a major flood event in the catchment of the River Ouse, Yorkshire, UK.
CATENA,
31(1-2), 53-75.
Author URL.
He Q, Walling DE (1997). The distribution of fallout Cs-137 and Pb-210 in undisturbed and cultivated soils.
APPLIED RADIATION AND ISOTOPES,
48(5), 677-690.
Author URL.
Walling DE (1997). The response of sediment yields to environmental change.
Author URL.
Owens PN, Walling DE, He QP, Shanahan J, Foster IDL (1997). The use of caesium-137 measurements to establish a sediment budget for the Start catchment, Devon, UK.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
42(3), 405-423.
Author URL.
Walling DE, He Q (1997). Use of fallout Cs-137 in investigations of overbank sediment deposition on river floodplains.
CATENA,
29(3-4), 263-282.
Author URL.
Collins AL, Walling DE, Leeks GJL (1997). Use of the geochemical record preserved in floodplain deposits to reconstruct recent changes in river basin sediment sources.
GEOMORPHOLOGY,
19(1-2), 151-167.
Author URL.
1996
Walling DE (1996). Erosion and sediment yield in a changing environment.
Author URL.
Walling DE, Webb BW (1996). Erosion and sediment yield: a global overview.
Author URL.
He Q, Walling DE (1996). Interpreting particle size effects in the adsorption of Cs-137 and unsupported Pb-210 by mineral soils and sediments.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY,
30(2), 117-137.
Author URL.
He Q, Walling DE, Owens PN (1996). Interpreting the Cs-137 profiles observed in several small lakes and reservoirs in southern England.
CHEMICAL GEOLOGY,
129(1-2), 115-131.
Author URL.
Webb BW, Walling DE (1996). Long-term variability in the thermal impact of river impoundment and regulation.
APPLIED GEOGRAPHY,
16(3), 211-223.
Author URL.
Brown T, Schneider H, Harper D (1996). Multi-scale estimates of erosion and sediment yields in the Upper Tana basin, Kenya.
Author URL.
He QP, Walling DE (1996). Rates of overbank sedimentation on the floodplains of British lowland rivers documented using fallout Cs-137.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
78A(4), 223-234.
Author URL.
Owens PN, Walling DE (1996). Spatial variability of caesium-137 inventories at reference sites: an example from two contrasting sites in England and zimbabwe.
APPLIED RADIATION AND ISOTOPES,
47(7), 699-707.
Author URL.
Walling DE (1996). Suspended sediment transport by rivers: a geomorphological and hydrological perspective.
Author URL.
Owens PN, Walling DE, He QP (1996). The behaviour of bomb-derived caesium-137 fallout in catchment soils.
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY,
32(3), 169-191.
Author URL.
Govers G, Quine TA, Desmet PJJ, Walling DE (1996). The relative contribution of soil tillage and overland flow erosion to soil redistribution on agricultural land.
EARTH SURFACE PROCESSES AND LANDFORMS,
21(10), 929-946.
Author URL.
Nicholas AP, Walling DE (1996). The significance of particle aggregation in the overbank deposition of suspended sediment on river floodplains.
Journal of Hydrology,
186(1-4), 275-293.
Abstract:
The significance of particle aggregation in the overbank deposition of suspended sediment on river floodplains
The effects of suspended sediment aggregation on rates of overbank deposition and on the grain size composition of deposited sediment were investigated using a combined field measurement and numerical modelling approach. Measurements of the in situ grain size characteristics of the suspended sediment load (termed the effective size distribution) of the River Culm, Devon, were obtained using a custom-built water elutriation system. Samples of suspended sediment and of sediment deposited on the floodplain were analysed in the laboratory to determine the size distributions of their constituent discrete mineral particles (termed the ultimate size distribution). Interpretation of these field data was aided by the development of a two-dimensional finite difference model of flood hydraulics and suspended sediment dispersion and deposition. Field measurements and model predictions show that particle aggregation results in higher relative contributions of fine size fractions to overbank deposits. Aggregation may also provide a mechanism for explaining the poor agreement between theoretical and observed trends in relationships between mean deposit grain size and distance from the main channel. Suspended sediment aggregation is shown to cause significant increases in rates of floodplain deposition. Increases in deposition rates resulting from aggregation may, however, be less than expected because of the effects of aggregate shape and density. The latter may offset increases in particle size so that the settling velocities of the largest aggregates do not increase appreciably with particle diameter.
Abstract.
He Q, Walling DE (1996). Use of fallout Pb-210 measurements to investigate longer-term rates and patterns of overbank sediment deposition on the floodplains of lowland rivers.
EARTH SURFACE PROCESSES AND LANDFORMS,
21(2), 141-154.
Author URL.
Webb BW, Walling DE, Zhang Y, Clark E (1996). Water temperature behaviour in South-West England.
Author URL.
1995
PHILLIPS JM, WALLING DE (1995). AN ASSESSMENT OF THE EFFECTS OF SAMPLE COLLECTION, STORAGE AND RESUSPENSION ON THE REPRESENTATIVENESS OF MEASUREMENTS OF THE EFFECTIVE PARTICLE-SIZE DISTRIBUTION OF FLUVIAL SUSPENDED SEDIMENT.
WATER RESEARCH,
29(11), 2498-2508.
Author URL.
PHILLIPS JM, WALLING DE (1995). MEASUREMENT IN-SITU OF THE EFFECTIVE PARTICLE-SIZE CHARACTERISTICS OF FLUVIAL SUSPENDED SEDIMENT BY MEANS OF a FIELD-PORTABLE LASER BACKSCATTER PROBE - SOME PRELIMINARY-RESULTS.
Author URL.
NICHOLAS AP, WALLING DE (1995). Modelling contemporary overbank sedimentation on floodplains: Some preliminary results.
Author URL.
WALLING DE, WOODWARD JC (1995). TRACING SOURCES OF SUSPENDED SEDIMENT IN RIVER BASINS - a CASE-STUDY OF THE RIVER CULM, DEVON, UK.
Author URL.
Webb BW, Walling DE (1995). The long-term thermal impact of reservoir operation and some ecological implications.
Author URL.
Walling DE, He Q, Quine TA (1995). Use of caesium-137 and lead-210 as tracers in soil erosion investigations.
Abstract:
Use of caesium-137 and lead-210 as tracers in soil erosion investigations
Abstract.
WALLING DE, QUINE TA, AGCY INTAE (1995). Use of fallout radionuclide measurements in soil erosion investigations.
Author URL.
1994
Quine TA, Desmet PJJ, Govers G, Vandaele K, Walling DE (1994). A comparison of the roles of tillage and water erosion in landform development and sediment export on agricultural land near Leuven, Belgium.
Abstract:
A comparison of the roles of tillage and water erosion in landform development and sediment export on agricultural land near Leuven, Belgium
Abstract.
ZHANG XB, QUINE TA, WALLING DE, LI Z (1994). APPLICATION OF THE CESIUM-137 TECHNIQUE IN a STUDY OF SOIL-EROSION ON GULLY SLOPES IN a YUAN AREA OF THE LOESS PLATEAU NEAR XIFENG, GANSU PROVINCE, CHINA.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
76(1-2), 103-120.
Author URL.
HIGGITT DL, WALLING DE, HAIGH MJ (1994). ESTIMATING RATES OF GROUND RETREAT ON MINING SPOILS USING CESIUM-137.
APPLIED GEOGRAPHY,
14(4), 294-307.
Author URL.
WALLING DE, HE Q (1994). RATES OF OVERBANK SEDIMENTATION ON THE FLOOD PLAINS OF SEVERAL BRITISH RIVERS DURING THE PAST 100 YEARS.
Author URL.
Quine TA, Navas A, Walling DE, Machin J (1994). Soil erosion and redistribution on cultivated and uncultivated land near las bardenas in the central Ebro river Basin, Spain.
Land Degradation & Development,
5(1), 41-55.
Abstract:
Soil erosion and redistribution on cultivated and uncultivated land near las bardenas in the central Ebro river Basin, Spain
The semiarid regions of Spain, including the central part of the Ebro River basin, are under threat due to desertification. Severe erosion, as a result of poor land management, has led to degradation of the soil resource, and there is a clear need for quantitative erosion rate data to evaluate the problem. This study aimed to examine the potential for using caesium‐137 to identify the patterns and rates of soil erosion and redistribution within this semiarid environment. Samples for the determination of caesium‐137 were collected from uncultivated slopes and cultivated valley floor sites near the head and outlet of a small representative basin in the Las Bardenas area. The measured patterns of caesium‐137 mobilization, redistribution and export provide a semiquantitative indication of the variation in erosion within the study site. Calibration of the caesium‐137 measurements, taking account of the differing behaviour of radiocaesium on cultivated and uncultivated land, allows estimation of the actual rates of erosion and deposition involved. The results show (1) the erosion rates on the cultivated land (1.6–2.5 kg m−2 yr−1) are typically more than five times those seen on the uncultivated land (0.2–0.4 kg m−2 yr−1), and (2) erosion on the uncultivated land is significantly less severe at the head of the basin than at the outlet. Study of the vegetation cover suggests that lower growing shrubs and grasses may be more effective in reducing erosion in this environment than trees. Copyright © 1994 Verlag Chemie, GmbH
Abstract.
1993
Walling DW, Woodward JC, Nicholas AP (1993). A multi-parameter approach to fingerprinting suspended-sediment sources.
Abstract:
A multi-parameter approach to fingerprinting suspended-sediment sources
Abstract.
Quine TA, Walling DE, Mandiringana OT (1993). An investigation of the influence of edaphic, topographic and land- use controls on soil erosion on agricultural land in the Borrowdale and Chinamora areas, Zimbabwe, based on caesium-137 measurements.
Abstract:
An investigation of the influence of edaphic, topographic and land- use controls on soil erosion on agricultural land in the Borrowdale and Chinamora areas, Zimbabwe, based on caesium-137 measurements
Abstract.
Quine TA, Walling DE (1993). Assessing recent rates of soil loss from areas of arable cultivation in the UK.
Abstract:
Assessing recent rates of soil loss from areas of arable cultivation in the UK
Abstract.
WALLING DE (1993). EROSION AND SEDIMENT YIELD RESEARCH - CURRENT STATUS AND NEEDS.
Author URL.
WEBB BW, WALLING DE (1993). LONGER-TERM WATER TEMPERATURE BEHAVIOR IN AN UPLAND STREAM.
HYDROLOGICAL PROCESSES,
7(1), 19-32.
Author URL.
WEBB BW, WALLING DE (1993). TEMPORAL VARIABILITY IN THE IMPACT OF RIVER REGULATION ON THERMAL REGIME AND SOME BIOLOGICAL IMPLICATIONS.
FRESHWATER BIOLOGY,
29(1), 167-182.
Author URL.
QUINE TA, WALLING DE, ZHANG X (1993). THE ROLE OF TILLAGE IN SOIL REDISTRIBUTION WITHIN TERRACED FIELDS ON THE LOESS PLATEAU, CHINA - AN INVESTIGATION USING CESIUM-137.
Author URL.
WALLING DE, WOODWARD JC (1993). USE OF a FIELD-BASED WATER ELUTRIATION SYSTEM FOR MONITORING THE IN-SITU PARTICLE-SIZE CHARACTERISTICS OF FLUVIAL SUSPENDED SEDIMENT.
WATER RESEARCH,
27(9), 1413-1421.
Author URL.
WALLING DE, HE Q (1993). USE OF CESIUM-137 AS a TRACER IN THE STUDY OF RATES AND PATTERNS OF FLOODPLAIN SEDIMENTATION.
Author URL.
Walling DE, Quine TA (1993). Using chernobyl-derived fallout radionuclides to investigate the role of downstream conveyance losses in the suspended sediment budget of the river severn, United Kingdom.
Physical Geography,
14(3), 239-253.
Abstract:
Using chernobyl-derived fallout radionuclides to investigate the role of downstream conveyance losses in the suspended sediment budget of the river severn, United Kingdom
The sediment budget concept offers a valuable tool for interpreting the processes of erosion and sediment yield operating in a drainage basin. However, it is often difficult to assemble the information necessary to establish a reliable sediment budget. Fallout radionuclides offer considerable potential for this purpose. This contribution describes how measurements of the fate of Chernobyl-derived 134Cs have been used to investigate the role of downstream conveyance losses associated with channel and floodplain storage in the suspended sediment budget of the 6850 km2 basin of the River Severn above Upton on Severn. The results relate to a 3-year period, 1986–1989, and indicate that conveyance losses associated with floodplain and channel storage respectively accounted for 23% and 2% of the total suspended sediment load passing through the main channel system. © 1993 Taylor & Francis Group, LLC.
Abstract.
1992
WOODWARD JC, WALLING DE (1992). A FIELD SAMPLING METHOD FOR OBTAINING REPRESENTATIVE SAMPLES OF COMPOSITE FLUVIAL SUSPENDED SEDIMENT PARTICLES FOR SEM ANALYSIS.
JOURNAL OF SEDIMENTARY PETROLOGY,
62(4), 742-744.
Author URL.
ROWAN JS, BRADLEY SB, WALLING DE (1992). FLUVIAL REDISTRIBUTION OF CHERNOBYL FALLOUT - RESERVOIR EVIDENCE IN THE SEVERN BASIN.
JOURNAL OF THE INSTITUTION OF WATER AND ENVIRONMENTAL MANAGEMENT,
6(6), 659-666.
Author URL.
Walling DE, Quine TA, Rowan JS (1992). Fluvial transport and redistribution of Chernobyl fallout radionuclides.
Hydrobiologia,
235-236(1), 231-246.
Abstract:
Fluvial transport and redistribution of Chernobyl fallout radionuclides
Fallout of Chernobyl-derived radionuclides over the UK evidenced marked spatial variation. Relatively high levels were recorded in central Wales, but they declined rapidly to the east and southeast. As a result, the headwaters of the River Severn received substantial inputs of fallout, whereas only low levels were recorded over the middle and lower reaches of its drainage basin. This situation afforded a valuable opportunity to investigate the sediment-associated transport of Chernobyl-derived radiocaesium through the 10 000 km2 drainage basin and its redistribution by fluvial processes. Information on the fallout inputs of radiocaesium has been obtained from the sampling of soil inventories across the basin. Measurements of the radiocaesium content of suspended sediment have been made at several sites on the main river over a period extending from before the Chernobyl disaster through to 1988. Concentrations of caesium-137 in the suspended sediment increased by two orders of magnitude immediately after the accident up to 1450 mBq g -1, declined rapidly subsequently, but remained almost an order of magnitude greater than the pre-Chernobyl levels throughout the remainder of the period (1986-1988). Downstream redistribution of radiocaesium has occurred as a result of deposition of sediment-associated radiocaesium in channel and floodplain sinks. It is estimated that 0.6% of the total fallout input of Chernobyl-derived caesium-134 has been transported out of the basin during the period 1986-1990. Estimates of channel and floodplain storage of sediment-associated caesium-134 at the time of sampling in 1988 and 1989 account for 0.01% and 0.2% of the total fallout input to the basin respectively. © 1992 Kluwer Academic Publishers.
Abstract.
WALLING DE, HE QP (1992). INTERPRETATION OF CESIUM-137 PROFILES IN LACUSTRINE AND OTHER SEDIMENTS - THE ROLE OF CATCHMENT-DERIVED INPUTS.
Author URL.
WEBB BW, WALLING DE (1992). LONG-TERM WATER TEMPERATURE BEHAVIOR AND TRENDS IN a DEVON, UK, RIVER SYSTEM.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
37(6), 567-580.
Author URL.
BATES PD, ANDERSON MG, BAIRD L, WALLING DE, SIMM D (1992). MODELING FLOODPLAIN FLOWS USING a 2-DIMENSIONAL FINITE-ELEMENT MODEL.
EARTH SURFACE PROCESSES AND LANDFORMS,
17(6), 575-588.
Author URL.
ROWAN JS, WALLING DE (1992). THE TRANSPORT AND FLUVIAL REDISTRIBUTION OF CHERNOBYL-DERIVED RADIOCESIUM WITHIN THE RIVER WYE BASIN, UK.
SCIENCE OF THE TOTAL ENVIRONMENT,
121, 109-131.
Author URL.
1991
Quine TA, Walling DE (1991). Rates of soil erosion on arable fields in Britain: quantitative data from caesium‐137 measurements.
Soil Use and Management,
7(4), 169-176.
Abstract:
Rates of soil erosion on arable fields in Britain: quantitative data from caesium‐137 measurements
Abstract. Despite a growing awareness that erosion on arable land in Britain is a potential hazard to long‐term productivity, there is still only limited information on the rates involved, particularly long‐term values. Use of the caesium‐137 (137Cs) technique to study soil erosion within arable fields on various soil types at 13 locations in southern Britain has yielded retrospective measurements of the long‐term (c. 30 years) rates of soil loss and the patterns of soil redistribution within the study fields. The range of long‐term rates of net soil loss extends from 0.61 per hectare per year on clay soils in Bedfordshire to 10.5 t per hectare per year on brown sands in Nottinghamshire. The measured rates are compared with other published data for similar soil types and land use, and the implications for long‐term productivity and potential environmental impacts are considered. Copyright © 1991, Wiley Blackwell. All rights reserved
Abstract.
WALLING DE, QUINE TA (1991). Use of <sup>137</sup>Cs measurements to investigate soil erosion on arable fields in the UK: potential applications and limitations.
Journal of Soil Science,
42(1), 147-165.
Abstract:
Use of 137Cs measurements to investigate soil erosion on arable fields in the UK: potential applications and limitations
Recent awareness of the potential hazard of soil erosion on arable land in the UK has highlighted the lack of reliable data concerning actual rates of soil loss. This lack of information reflects both a low level of interest, and the lack of a simple and generally applicable method of documenting long‐term rates of soil loss. Existing methods involving the use of hazard classification procedures and direct measurement techniques, including erosion plots and field surveys, all possess significant limitations. The use of 137Cs measurements to provide information on rates of soil loss and deposition averaged over the past 30 years would appear to offer considerable potential. The results of applying this approach to three arable fields on contrasting soil types in Britain are reported. These results confirm the viability of the technique and its potential for providing information on patterns and rates of erosion and deposition within individual fields and their overall sediment budgets. Limitations include the restricted size of the areas that can be investigated and the need to take account of additional inputs of 137Cs derived from the Chernobyl accident. Copyright © 1991, Wiley Blackwell. All rights reserved
Abstract.
1989
WALLING DE, MOOREHEAD PW (1989). THE PARTICLE-SIZE CHARACTERISTICS OF FLUVIAL SUSPENDED SEDIMENT - AN OVERVIEW.
HYDROBIOLOGIA,
176, 125-149.
Author URL.
WALLING DE (1989). WATER - PROVISION AND CONTROL.
GEOGRAPHY,
74(325), 356-358.
Author URL.
1988
WALLING DE (1988). EROSION AND SEDIMENT YIELD RESEARCH - SOME RECENT PERSPECTIVES.
JOURNAL OF HYDROLOGY,
100(1-3), 113-141.
Author URL.
ARANUVACHAPUN S, WALLING DE (1988). LANDSAT-MSS RADIANCE AS a MEASURE OF SUSPENDED SEDIMENT IN THE LOWER YELLOW RIVER (HWANG HO).
REMOTE SENSING OF ENVIRONMENT,
25(2), 145-165.
Author URL.
Lambert CP, Walling DE (1988). Measurement of channel storage of suspended sediment in a gravel-bed river.
Catena,
15(1), 65-80.
Abstract:
Measurement of channel storage of suspended sediment in a gravel-bed river
An examination of suspended sediment storage within a 35 km stretch of the main channel of the River Exe, Devon, UK, has been undertaken and some results are presented in this paper. Methodological problems associated with a field investigation of this nature are outlined and a technique for measuring suspended sediment storage in gravel-bed rivers is documented. The findings of the study indicate that for the River Exe, channel storage of suspended sediment is minimal and equivalent to less than two per cent of the annual sediment yield. In this river the main channel acts primarily as an efficient conveyance system through which sediment is rapidly transported from the basin. © 1988.
Abstract.
WALLING DE, BRADLEY SB (1988). TRANSPORT AND REDISTRIBUTION OF CHERNOBYL FALLOUT RADIONUCLIDES BY FLUVIAL PROCESSES - SOME PRELIMINARY EVIDENCE.
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH,
10(2), 35-39.
Author URL.
1987
LAMBERT CP, WALLING DE (1987). FLOODPLAIN SEDIMENTATION - a PRELIMINARY INVESTIGATION OF CONTEMPORARY DEPOSITION WITHIN THE LOWER REACHES OF THE RIVER CULM, DEVON, UK.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
69(3-4), 393-404.
Author URL.
WALLING DE (1987). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
11(1), 112-120.
Author URL.
WALLING DE (1987). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
11(4), 590-597.
Author URL.
WALLING DE, MOOREHEAD PW (1987). SPATIAL AND TEMPORAL VARIATION OF THE PARTICLE-SIZE CHARACTERISTICS OF FLUVIAL SUSPENDED SEDIMENT.
GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY,
69(1), 47-59.
Author URL.
GILBEY J, BRADLEY S, WALLING DE (1987). THE DEPOSITION OF CESIUM-137 ON GRASSLAND AT a SITE IN SW ENGLAND FOLLOWING THE CHERNOBYL ACCIDENT.
GRASS AND FORAGE SCIENCE,
42(4), 439-442.
Author URL.
ARANUVACHAPUN S, WALLING DE (1987). THE USE OF a MICROCOMPUTER FOR IMAGE-ANALYSIS.
INTERNATIONAL JOURNAL OF REMOTE SENSING,
8(9), 1385-1397.
Author URL.
1986
WALLING DE (1986). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
10(1), 69-80.
Author URL.
WEBB BW, WALLING DE (1986). SPATIAL VARIATION OF WATER TEMPERATURE CHARACTERISTICS AND BEHAVIOR IN a DEVON RIVER SYSTEM.
FRESHWATER BIOLOGY,
16(5), 585-608.
Author URL.
1985
WALLING DE, WEBB BW (1985). ESTIMATING THE DISCHARGE OF CONTAMINANTS TO COASTAL WATERS BY RIVERS - SOME CAUTIONARY COMMENTS.
MARINE POLLUTION BULLETIN,
16(12), 488-492.
Author URL.
WEBB BW, WALLING DE (1985). NITRATE BEHAVIOR IN STREAMFLOW FROM a GRASSLAND CATCHMENT IN DEVON, UK.
WATER RESEARCH,
19(8), 1005-1016.
Author URL.
WALLING DE (1985). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
9(1), 97-103.
Author URL.
WEBB BW, WALLING DE (1985). TEMPORAL VARIATION OF RIVER WATER TEMPERATURES IN a DEVON RIVER SYSTEM.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
30(4), 449-464.
Author URL.
1984
BURT TP, TRUDGILL ST, WALLING DE, ARKEL B, THOMAS AD (1984). HILLSLOPE HYDROLOGY AND ITS RELATIONSHIP TO NITRATE SOURCES IN a CATCHMENT OF MIXED LAND-USE.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE,
35(8), 857-859.
Author URL.
WEBB BW, WALLING DE (1984). NITRATE LEVELS IN DEVON CATCHMENTS.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE,
35(8), 851-852.
Author URL.
WALLING DE (1984). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
8(1), 129-138.
Author URL.
WALLING DE, THORNTON R (1984). THE ROLE OF SUSPENDED SEDIMENT IN CATCHMENT NUTRIENT BUDGETS.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE,
35(8), 856-857.
Author URL.
1983
WALLING DE, WEBB BW (1983). GLOBAL PATTERNS OF EROSION - a CHANGING PERSPECTIVE.
JOURNAL OF THE GEOLOGICAL SOCIETY,
140(MAR), 321-321.
Author URL.
WALLING DE (1983). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
7(1), 97-112.
Author URL.
WALLING DE (1983). THE SEDIMENT DELIVERY PROBLEM.
JOURNAL OF HYDROLOGY,
65(1-3), 209-237.
Author URL.
1982
PEART MR, WALLING DE (1982). PARTICLE-SIZE CHARACTERISTICS OF FLUVIAL SUSPENDED SEDIMENT.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
27(2), 248-248.
Author URL.
WALLING DE (1982). PHYSICAL HYDROLOGY.
PROGRESS IN PHYSICAL GEOGRAPHY,
6(1), 122-133.
Author URL.
WALLING DE, WEBB BW (1982). SEDIMENT AVAILABILITY AND THE PREDICTION OF STORM-PERIOD SEDIMENT YIELDS.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
27(2), 246-246.
Author URL.
WALLING DE (1982). SUSPENDED SEDIMENT PROPERTIES AND THEIR GEOMORPHOLOGICAL SIGNIFICANCE.
JOURNAL OF THE GEOLOGICAL SOCIETY,
139(MAR), 212-212.
Author URL.
WALLING DE, KANE P (1982). TEMPORAL VARIATION OF SUSPENDED SEDIMENT PROPERTIES.
HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES,
27(2), 248-249.
Author URL.
1980
WALLING DE, WEBB BW (1980). THE SPATIAL DIMENSION IN THE INTERPRETATION OF STREAM SOLUTE BEHAVIOR.
JOURNAL OF HYDROLOGY,
47(1-2), 129-149.
Author URL.
1979
OLDFIELD F, RUMMERY TA, THOMPSON R, WALLING DE (1979). IDENTIFICATION OF SUSPENDED SEDIMENT SOURCES BY MEANS OF MAGNETIC MEASUREMENTS - SOME PRELIMINARY-RESULTS.
WATER RESOURCES RESEARCH,
15(2), 211-218.
Author URL.
WALLING DE, PEART MR, OLDFIELD F, THOMPSON R (1979). SUSPENDED SEDIMENT SOURCES IDENTIFIED BY MAGNETIC MEASUREMENTS.
NATURE,
281(5727), 110-113.
Author URL.
1978
FOSTER IDL, WALLING DE (1978). EFFECTS OF 1976 DROUGHT AND AUTUMN RAINFALL ON STREAM SOLUTE LEVELS.
EARTH SURFACE PROCESSES AND LANDFORMS,
3(4), 393-406.
Author URL.
OLDFIELD F, RUMMERY TA, THOMPSON R, WALLING DE (1978). IDENTIFYING SOURCES OF SUSPENDED SEDIMENTS IN STREAMS BY MEANS OF MAGNETIC MEASUREMENTS.
GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY,
53(1), 146-146.
Author URL.
WALLING DE, WEBB BW (1978). MAPPING SOLUTE LOADINGS IN AN AREA OF DEVON, ENGLAND.
EARTH SURFACE PROCESSES AND LANDFORMS,
3(1), 85-99.
Author URL.
1977
WALLING DE (1977). ASSESSING ACCURACY OF SUSPENDED SEDIMENT RATING CURVES FOR a SMALL BASIN.
WATER RESOURCES RESEARCH,
13(3), 530-538.
Author URL.
1975
WALLING DE (1975). SOLUTE VARIATIONS IN SMALL CATCHMENT STREAMS.
TRANSACTIONS OF THE INSTITUTE OF BRITISH GEOGRAPHERS(64), 141-147.
Author URL.
WALLING DE, WEBB BW (1975). SPATIAL VARIATION OF RIVER WATER-QUALITY - SURVEY OF RIVER EXE.
TRANSACTIONS OF THE INSTITUTE OF BRITISH GEOGRAPHERS(65), 155-171.
Author URL.
WALLING DE, FOSTER IDL (1975). VARIATIONS IN NATURAL CHEMICAL CONCENTRATION OF RIVER WATER DURING FLOOD FLOWS, AND LAG EFFECT - SOME FURTHER COMMENTS.
JOURNAL OF HYDROLOGY,
26(3-4), 237-244.
Author URL.
1971
GREGORY KJ, WALLING DE (1971). FIELD MEASUREMENTS IN DRAINAGE BASIN.
GEOGRAPHY,
56(253), 277-292.
Author URL.