The hydrological function of organo-mineral soils in downstream flood risk

Lead Research Organisation: University of Leeds
Department Name: Sch of Geography

Abstract

This project will seek to understand hydrological processes operating in upland organo-mineral soils and how their management and vegetation cover influences river flow peaks. This novel field, lab and modelling project will expand our knowledge on the function and hydrology of upland soils which are of high conservation value. The project will directly provide Natural England with urgently needed management decision-making evidence on upland soil management for flood peak reduction. Organo-mineral soils cover around 20 % of the UK, and are particularly common in upland areas with the main types being stagnohumic gleys and acid brown earths. Unlike peatlands, the function and hydrology of organo-mineral soils is globally very poorly understood with major gaps in the literature. These soils typically underlie upland heathland and grasslands in areas with high conservation value. It is unclear whether these soils are dominated by throughflow (and what their typical permeability range is), infiltration-excess overland flow or saturation-excess overland flow in different topographic contexts and rainfall events. It is also unclear how management of organo-mineral soils impacts their role in runoff generation.

There is an urgent need for evidence on 'nature-based' flood management solutions, particularly in UK uplands - source areas for the UK's major rivers. Recent modelling work on peatlands by U. Leeds has shown that controlling overland flow velocities by changing the surface cover conditions in key spatially identifiable parts of the catchment can play an important role in reducing flood peaks (by up to 20 % for some rainfall events). However, we do not have data from organo-mineral soils, which are likely to function quite differently to peat, to inform such modelling and so practitioners have limited basis for upland management decisions which may benefit those downstream at risk of flooding.

Study design: The above issues will be tackled through a combined monitoring, experimental and modelling approach providing PhD skills benefits involving: 1) Measure and determine the dominant hydrological pathways (e.g. overland flow, subsurface flow) through monitoring of flow volumes / rates though and over stagnohumic gleys and acid brown earths (controlling for slope position using the topographic index), moisture content & water-table depths; 2) permeability tests to measure the hydraulic conductivity (U. Leeds have a novel permeameter system allowing 25 soil samples to be tested simultaneously, allowing high throughput); 3) experimental overland flow velocity measurements by supplying water to plots and measuring the velocities for different slope angles, flow depths and vegetation conditions. The above three approaches will be used on areas of hillslope in Cumbria to test for differences in hydrological function related to soil condition and surface cover. The design will incorporate soils that have been assessed by Natural England to be in different states of degradation including high quality Atlantic Heath (dense dwarf shrubs with an understory of mosses), poor Atlantic heath, good acid grassland and acid grassland that has heavy grazing.

The three field and laboratory steps above will then enable the student to: 4) modify a new spatially-distributed version of TOPMODEL recently developed by U. Leeds; 5) use the model to test different spatial organo-mineral land-cover scenarios to test optimal solutions to reduce downstream flow peaks.

Publications

10 25 50
 
Description Research is still ongoing however the following are key finding so far (Feb 2020):
- Vegetative surface roughness has a significant influence over overland flow velocity in upland grassland habitats and the extent of influence in 'slowing the flow' is seasonal, depending on growth, decay and management of vegetation/habitat types
- In response to the same applied flow event, overland flow velocity in a haymeadow can be up to 50% faster than in a rank grassland
Exploitation Route To use the results in flood modelling to better inform how land use contributes to flood mitigation. Also, to inform natural flood management initiatives, such as which habitats are the best to promote for reducing overland flow velocity.
Sectors Agriculture, Food and Drink,Environment,Government, Democracy and Justice

 
Description Natural England CASE partner 
Organisation Natural England
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Provision of research in areas of interest to Natural England. Expertise in hydrology, soils and vegetation research. Data analysis and figures they are able to use to improve services within Natural England.
Collaborator Contribution Training in vegetation identification and mountain navigation training. Introduction to other collaborative partners. Direction towards areas of research most relevant towards industrial stakeholders. SSSI permission applications. Career advice and work experience shadowing.
Impact Multidisciplinary: Ecology, Hydrology, Flood management, Farming practice, Legal processes and policy
Start Year 2018
 
Description RSPB Haweswater Partnership: RSPB and United Utilities 
Organisation Royal Society for the Protection of Birds (RSPB)
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Research carried out on United Utilities owned (RSPB tenanted) land. Research data and outcomes made freely available to both companies to inform them on the current state of their land, success/failure of management processes researched, and ways they could change management processes.
Collaborator Contribution Free accommodation at the RSPB Haweswater farmhouse. Storage and transport of equipment. Advice about the local environment and how they currently manage the land. Land access permissions. Introduction to Lake District based collaborators.
Impact Multidisciplinary: Land owners, land managers, ecologists, hydrologists Outcomes: Talks at Haweswater research conference
Start Year 2018
 
Description RSPB Haweswater Partnership: RSPB and United Utilities 
Organisation United Utilities Group PLC
Country United Kingdom 
Sector Private 
PI Contribution Research carried out on United Utilities owned (RSPB tenanted) land. Research data and outcomes made freely available to both companies to inform them on the current state of their land, success/failure of management processes researched, and ways they could change management processes.
Collaborator Contribution Free accommodation at the RSPB Haweswater farmhouse. Storage and transport of equipment. Advice about the local environment and how they currently manage the land. Land access permissions. Introduction to Lake District based collaborators.
Impact Multidisciplinary: Land owners, land managers, ecologists, hydrologists Outcomes: Talks at Haweswater research conference
Start Year 2018
 
Description River Basins Processes and Management Research Cluster 
Organisation University of Leeds
Department School of Geography Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution Research expertise and opportunities for further research
Collaborator Contribution Research expertise and opportunities for further research, advice on funding and conference presentations, introduction to external collaborators
Impact Natural Flood Management specialist interest group Multidisciplinary: ecology, hydrology, glaciology
Start Year 2018
 
Description water@leeds 
Organisation water@leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution Presentation of research, provision of expertise
Collaborator Contribution Provision of expertise, introduction to researchers in a similar research field for potential collaborations
Impact Multidisciplinary: physical, biological, chemical, social and economic sciences, engineering and the arts
Start Year 2018
 
Description Catchment Summer School, University of Birmingham 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Attended the 5 day Catchment Summer School held at the University of Birmingham. This involved a week of receiving teaching and advice on catchment hydrology, including sharing my own research projects. I was able to meet people undertaking similar research and ask specific questions about study methods (sensors/fieldwork/paper writing) which were invaluable to developing my PhD.
Year(s) Of Engagement Activity 2018
URL https://www.birmingham.ac.uk/research/water-sciences/summer-school/index.aspx
 
Description Lake District Research Stakeholder Discussion Group 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact A whole-day presentation and discussion meeting between Lake District stakeholders including Environment Agency, RSPB, United Utilities, Woodland Trust, JBA Consulting, National Trust and University partnerships. The purpose of the meeting was to present and discuss current research occurring in the Lake District, to encourage communication between groups and highlight future research opportunities.
Year(s) Of Engagement Activity 2018
 
Description NERC Advanced Training Short Course: Natural Flood Risk Management 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Attendance at the NFM course which covered:

• Fundamentals of hydrological processes and measurement with field exercises
• Evaluation of the NFRM evidence base
• NFRM framework illustrated with exercises in opportunity mapping, modelling and stakeholder co-production
• Flood 'event set' analyses using hands-on 2D flood inundation modelling and physical sandbox modelling
• Risk & resilience estimation with spatial joint probability analysis
• Detailed NFRM modelling practical using Dynamic-Topmodel with uncertainty estimation including decision analysis software
• Co-benefits of NFRM with hands-on Benefits-Cost analyses

Discussed the research project with postgraduate students and industry professionals to gain insight into NFM and apply it to the PhD project. Presented my (proposed) work and got invaluable feedback for how best to proceed. Made good links to other universities
Year(s) Of Engagement Activity 2017
URL https://www.therrc.co.uk/events/nerc-advanced-training-short-course-natural-flood-risk-management
 
Description Poster presentation and presentation slide at 'Natural Flood Management: Does it work?' British Hydrological Society National Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presented a poster for the British Hydrological Society meeting. The initial flume research was also included as part of a presentation slide by a member of University of Leeds River Basins Processes and Management Research Cluster. These two presentation methods led to discussions with the University of Manchester and University of Lancaster about future research collaborations. Following this, The University of Manchester shared overland flow sensor designs in return for details on the hillslope flume design and a technician from the University of Lancaster helped with some fieldwork to see the flume working.
Year(s) Of Engagement Activity 2019
URL http://www.hydrology.org.uk/assets/BHS_NFM_24042019_flyer.pdf
 
Description Presentation for the River Basins Processes and Management Research Cluster 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Presentation to the River Basins Processes and Management Research Cluster at the University of Leeds to highlight Natural Flood Management (NFM) research. Following this presentation, and presentations of similar work, a NFM specialist interest group was formed to share ideas and collaborate on fieldwork/data analysis.
Year(s) Of Engagement Activity 2018
URL https://environment.leeds.ac.uk/geography-research-river-basin-processes-management
 
Description water@leeds Lightning Talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Presentation to academics and research partners who are involved with water@leeds, one of the largest interdisciplinary centres for water research in any university in the world. The research was discussed after the presentation with a variety of academics from disciplines across the University of Leeds.
Year(s) Of Engagement Activity 2018
URL https://water.leeds.ac.uk/about-us/