Assessing the eco-hydrological and geomorphic effects of floodplain restoration

Supervisors: Claire Walsh (NU), Stephen Addy (James Hutton Institute), Hannah Clilverd (UKCEH), Robin Pakeman (James Hutton Institute) Justine Thompson (UCL)

Contact email: Claire.Walsh@ncl.ac.uk

Location: Newcastle

Project Rational: Naturally functioning floodplains provide a range of ecosystem services. Through hydrological connections to rivers, they store water helping to attenuate floods and maintain baseflows during droughts. They also facilitate biogeochemical processing of nutrients, aiding water quality remediation, and carbon sequestration. Despite their relatively small area, floodplains support a disproportionately high biodiversity due to dynamic geomorphic and hydrological processes that create a variety of habitats. The conservation and restoration of healthy floodplains potentially could mitigate the projected increasing frequency of extremes of flooding and drought associated with climate change and reverse biodiversity losses. Understanding of the hydro-ecology of restored floodplains is not well constrained due to a lack of studies mostly confined to lowland rivers. Upland floodplains remain understudied; they differ having lower nutrient status and higher energy. Restoration of floodplains often involves removal of flood embankments and riverbank erosion protection. Removing these constraints could lead to increased channel movement and the re-development of complex river and floodplain features. Increased duration and frequency of flooding could influence vegetation communities by modifying waterlogging, nutrient deposition and seed dispersal. Understanding floodplain responses to these multifaceted drivers of change and their controls will help underpin successful management of floodplains and plan restoration projects.

Methodology: This study will be mainly centered on the Mar floodplain near Braemar in the Cairngorms National Park and will build on earlier monitoring through considering a wider area of the floodplain. Repeated detailed topographical surveys using a differential Global Positioning System (dGPS) will be used to quantify changes in geomorphology. Changes in water table pre- and post-restoration will be monitored using the existing network of piezometers distributed across the floodplain and additional piezometers installed. Additional measurements, for example soil moisture and groundwater oxygen concentrations within the restored floodplain, will also be taken to provide additional insights. New vegetation quadrats will be established in representative vegetation communities to assess the distribution of vascular and non-vascular plants. Vegetation data will then be modelled as a function of piezometer water level observations and other potential environmental controls to understand current hydro-ecological associations. Changes in vegetation communities in response to hydrological modifications initiated by the restoration are likely to be too slow for the duration of the project. Modelling will, however, enable the simulation of the hydrological impacts of the restoration under both current and projected future climate which will, in turn, permit assessment of potential vegetation responses.

Background Reading:
Addy, S. and Wilkinson, M.E., 2021. Embankment lowering and natural self-recovery improves river-floodplain hydro-geomorphic connectivity of a gravel bed river. Science of The Total Environment, 770, p.144626.

Clilverd, H.M., Thompson, J.R., Sayer, C.D., Heppell, C.M., Axmacher, J.C., Stratford, C. and Burningham, H., 2022. Simulated effects of floodplain restoration on plant community types. Applied Vegetation Science, 25(4), p.e12697.

Thompson, J.R., Cliverd, H.M., Zheng, J., Iravani, H., Sayer, C.D., Heppell, C.M., Axmacher, J.C. (2023). Revisiting hydro-ecological impacts of climate change on a restored floodplain wetland via hydrological/hydraulic modelling and the UK Climate Projections 2018 scenarios. Wetlands 43(6), pp 71.

FLOOD-CDT
This PhD is being advertised as part of the Centre for Doctoral Training for Resilient Flood Futures (FLOOD-CDT). Further details about FLOOD-CDT can be seen here https://flood-cdt.ac.uk. Please note, that your application will be assessed upon: (1) Motivation and Career Aspirations; (2) Potential & Intellectual Excellence; (3) Suitability for specific project and (4) Fit to FLOOD-CDT. So please familiarise yourselves with FLOOD-CDT before applying. During the application process candidates will need to upload:
• a 1 page statement of your research interests in flooding and FLOOD-CDT and your rationale for your choice of project;
• a curriculum vitae giving details of your academic record and stating your research interests;
• name two current academic referees together with an institutional email addresses; on submission of your online application your referees will be automatically emailed requesting they send a reference to us directly by email;
• academic transcripts and degree certificates (translated if not in English) - if you have completed both a BSc & an MSc, we require both; and
• a IELTS/TOEFL certificate, if applicable.
Please upload all documents in PDF format. You are encouraged to contact potential supervisors by email to discuss project-specific aspects of the proposed prior to submitting your application. If you have any general questions please contact floodcdt@soton.ac.uk.

Apply
Apply for this PhD here: https://www.ncl.ac.uk/postgraduate/fees-funding/search-funding/?code=FLO...

Location: 
Newcastle

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