Overview
I’ve always been interested in how we interact with our environment. I studied geography with Exeter at the Cornwall Campus, then moved on to Durham University to study environmental risk. My master’s dissertation investigated the potential of soil to reduce flood risk in Northumberland in partnership with Northumbrian Water. The project, alongside experiencing my own home flooding twice, secured my interest in using our natural environment to manage floods in the UK. This led me to my current PhD in partnership with Devon Wildlife Trust and the Environment Agency, researching the natural flood management potential of Culm grassland in North Devon.
Broad research specialisms:
Hydrology, pedology, ecology
Qualifications
BSc (Hons) Physical Geography, University of Exeter
MSc Risk, Durham University
Research
Research projects
Project Title: Can unimproved grasslands deliver natural flood management alongside environmental benefits?
Supervisors: Prof R Brazier, Dr K Anderson (University of Exeter), Ms L Schneidau (Devon Wildlife Trust), Dr R Smith (Environment Agency)
Funding Body: Devon Wildlife Trust, Environment Agency, University of Exeter
Project Description:
The research project explores the value of unimproved grasslands in North Devon, also known as Culm Grassland or Rhos pasture, as a form of natural flood management. This reflects the current shift in flood management away from engineering structures, and instead the use of natural processes to attenuate flood impacts alongside multiple environmental and social benefits.
The Culm grasslands are a highly fragmented habitat, with only 10% of grassland remaining in comparison with 1950 extent. This reduction is largely due to the expansion of agriculture and the abandonment of the habitat. The grassland is a vital ecosystem, supporting species such as the Marsh Fritillary Butterfly (a top ten EU endangered species). The unimproved grassland has been shown to have water retention properties, alongside other environmental benefits such as water quality regulation, mitigation of soil erosion and as a storage of carbon. This research project aims to explore the multiple benefits offered by this unique but fragmented habitat, contributing to ongoing efforts to restore the grassland and improve local environments.
Publications
Key publications | Publications by category | Publications by year
Publications by category
Journal articles
Ellis N, Brazier R, Anderson K (2021). Comparing fine‐scale structural and hydrologic connectivity within unimproved and improved grassland. Ecohydrology, 14(7).
Ellis N, Anderson K, Brazier R (2021). Mainstreaming natural flood management: a proposed research framework derived from a critical evaluation of current knowledge.
Progress in Physical Geography: Earth and Environment,
45(6), 819-841.
Abstract:
Mainstreaming natural flood management: a proposed research framework derived from a critical evaluation of current knowledge
Natural flood management (NFM), or working with natural processes, is a growing flood risk management method in the UK, Europe and worldwide. However, unlike the current dominant technical flood management, it lacks an established evidence base of flood risk parameters. This lack of evidence base can limit the uptake of NFM as a flood management method. This paper critically evaluates examples of NFM and wider relevant literature in order to identify NFM knowledge gaps and suggest how to overcome these. The UK is used as a microcosm of different environments for diverse examples. The sections include: land cover, land management, landscape interactions and trade-offs, evaluating the wider benefits of NFM and, finally, scaling from plot to catchment. This concludes in a suggested framework for a new approach to NFM research, which encompasses spatial scales, interactions and trade-offs of NFM and consistency of reporting results. Widening the NFM empirical evidence base should be seen as an opportunity for a new approach to flood research through exploring new habitats and new flood resilience methods.
Abstract.
Rodway-Dyer S, Ellis N (2018). Combining remote sensing and on-site monitoring methods to investigate footpath erosion within a popular recreational heathland environment.
Journal of Environmental Management,
215, 68-78.
Abstract:
Combining remote sensing and on-site monitoring methods to investigate footpath erosion within a popular recreational heathland environment
Footpaths are a prominent consequence of natural area tourism and reflect damage caused to valuable, sensitive habitats by people pressure. Degradation impacts on vegetation, wildlife, on and off-site soil movement and loss, creation of additional informal off-path footpaths (desire lines), and visual destruction of landscapes. Impacts need to be measured and monitored on a large temporal and spatial scale to aid in land management to maintain access and preserve natural environments. This study combined remote sensing (Light Detection and Ranging [LiDAR] and aerial photography) with on-site measurement of footpaths within a sensitive heathland habitat (Land's End, Cornwall, UK). Soil loss, slope angle change, vegetation damage and a hydrology model were combined to comprehensively study the site. Results showed 0.09 m mean soil loss over five years, footpath widening, increasing grass cover into heathland, and water channelling on the footpaths exacerbating erosion. The environments surrounding the footpaths were affected with visitors walking off path, requiring further management and monitoring. Multiple remote sensing techniques were highly successful in comprehensively assessing the area, particularly the hydrology model, demonstrating the potential of providing a valuable objective and quantitative monitoring and management tool.
Abstract.
Publications by year
2022
Ellis N (2022). Understanding the capacity of unimproved grassland to deliver natural flood management.
Abstract:
Understanding the capacity of unimproved grassland to deliver natural flood management
Natural flood management (NFM) is an emerging form of land management which works with natural processes to reduce flood risk. The evidence basis for NFM schemes is immature but is growing, with wetland unimproved grassland being a particularly
understudied ecosystem in need of evidence-based research. The research presented in this thesis aimed to assess the extent to which unimproved grassland, a formerly extensive habitat that has been greatly reduced by intensive agriculture, could provide NFM benefits. This study specifically focused on unimproved grassland in southwest England known as Culm grassland; comprising of purple moor grass (Molinia caerulea) and rush pasture (Juncus effusus). Improved grassland (Lolium perenne) fields were used as a comparison/control as the grassland species which now dominates North-west European agricultural landscapes.
The study was divided into four objectives spanning a range of spatial scales to gain a multi-scale understanding of unimproved grassland hydrology. Objective 1 focused upon soil and water table properties using soil sampling and water table monitoring via dipwells. Results showed that M. caerulea and J. effusus dominated fields had on average significantly less compacted soil and slowly released water after rainfall events, compared to the more compacted and flashier L. perenne dominated sites. The research was continued in Objective
2 which used a rainfall simulator to mimic a 40 mm/hr rainfall event over plots of the three grassland types. Results showed a significant relationship between soil compaction and when saturation was reached, but volume of runoff was likely influenced by vegetation density within each plot, as no clear relationship between grassland type and overland flow was found. Objective 3 quantified surface flow pathway length in a field of M. caerulea and L. perenne using an unpiloted aerial vehicle and structure from motion photogrammetry to produce a detailed surface model through which surface flow pathways could be measured. The M. caerulea field had on average 1.4 times greater flow pathway length than the L. perenne control field and a rougher round/vegetation surface which could delay and store surface water. All three field experiments fed into Objective 4: sub-catchment rainfall-runoff response modelling of the Upper Tamar. Scenarios of 0, 10, 20 and 30% unimproved grassland restoration were modelled to assess potential impacts on within river flood hydrographs. Results showed peak flow and peak volume were reduced with increasing unimproved grassland extent. The four objectives of this study showed that unimproved grassland restoration has a place in the NFM toolkit, and that unimproved grassland can deliver other environmental benefits such as greater carbon storage and a diverse habitat for wildlife.
Abstract.
2021
Ellis N, Brazier R, Anderson K (2021). Comparing fine‐scale structural and hydrologic connectivity within unimproved and improved grassland. Ecohydrology, 14(7).
Ellis N, Anderson K, Brazier R (2021). Mainstreaming natural flood management: a proposed research framework derived from a critical evaluation of current knowledge.
Progress in Physical Geography: Earth and Environment,
45(6), 819-841.
Abstract:
Mainstreaming natural flood management: a proposed research framework derived from a critical evaluation of current knowledge
Natural flood management (NFM), or working with natural processes, is a growing flood risk management method in the UK, Europe and worldwide. However, unlike the current dominant technical flood management, it lacks an established evidence base of flood risk parameters. This lack of evidence base can limit the uptake of NFM as a flood management method. This paper critically evaluates examples of NFM and wider relevant literature in order to identify NFM knowledge gaps and suggest how to overcome these. The UK is used as a microcosm of different environments for diverse examples. The sections include: land cover, land management, landscape interactions and trade-offs, evaluating the wider benefits of NFM and, finally, scaling from plot to catchment. This concludes in a suggested framework for a new approach to NFM research, which encompasses spatial scales, interactions and trade-offs of NFM and consistency of reporting results. Widening the NFM empirical evidence base should be seen as an opportunity for a new approach to flood research through exploring new habitats and new flood resilience methods.
Abstract.
2018
Rodway-Dyer S, Ellis N (2018). Combining remote sensing and on-site monitoring methods to investigate footpath erosion within a popular recreational heathland environment.
Journal of Environmental Management,
215, 68-78.
Abstract:
Combining remote sensing and on-site monitoring methods to investigate footpath erosion within a popular recreational heathland environment
Footpaths are a prominent consequence of natural area tourism and reflect damage caused to valuable, sensitive habitats by people pressure. Degradation impacts on vegetation, wildlife, on and off-site soil movement and loss, creation of additional informal off-path footpaths (desire lines), and visual destruction of landscapes. Impacts need to be measured and monitored on a large temporal and spatial scale to aid in land management to maintain access and preserve natural environments. This study combined remote sensing (Light Detection and Ranging [LiDAR] and aerial photography) with on-site measurement of footpaths within a sensitive heathland habitat (Land's End, Cornwall, UK). Soil loss, slope angle change, vegetation damage and a hydrology model were combined to comprehensively study the site. Results showed 0.09 m mean soil loss over five years, footpath widening, increasing grass cover into heathland, and water channelling on the footpaths exacerbating erosion. The environments surrounding the footpaths were affected with visitors walking off path, requiring further management and monitoring. Multiple remote sensing techniques were highly successful in comprehensively assessing the area, particularly the hydrology model, demonstrating the potential of providing a valuable objective and quantitative monitoring and management tool.
Abstract.
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