Using environmental tracers to test the effectiveness of Natural Flood Management techniques

Recent flooding in Yorkshire and other parts of the UK has highlighted the need for improved flood management techniques and infrastructure to mitigate the increasing frequency and magnitude of flood events. In addition to the continued use of hard engineering techniques to protect areas from flood impacts, recent policies and government advice have recommended that more ‘natural’ and sustainable flood management techniques should be employed, where possible, to help deliver flood risk management. Natural flood management (NFM) refers to the use of natural catchment-scale features to manage the sources and pathways of flood waters to delay, reduce or alter the flood pulse in a way which reduces flood risk. There are a number of NFM techniques which are often used, including reconnection of floodplains, land use management, runoff attenuation features and in-channel modifications, however the take-up and use of NFM has been slow, predominantly due to the lack of empirical data and evidence of its effectiveness in comparison with more traditional hard engineering approaches. In addition, the potential for NFM measures to increase flood risk in some situations and locations through changes in land use, instream features and alteration of hydrological pathways have been reported which further discourages land managers in utilising NFM techniques.

Environmental tracers have long been used to assess hydrological flow paths in catchments, providing information on the source, route and residence time of water. High-frequency sampling of environmental tracers in catchments where NFM measures have been utilised has the potential to provide the empirical evidence required to ascertain how NFM can reduce the magnitude, timing and peak flood flows. Such information would offer the first experiential data of NFM effectiveness to help inform future land and flood risk management and stakeholder engagement in NFM measures.

This studentship will address the lack of robust, empirical BACI- style evidence currently limiting NFM research by utilising novel environmental tracer techniques to determine if NFM measures can delay, reduce and desynchronise the flood hydrograph and therefore reduce flood risk. The student will address questions such as: which NFM measures are most effective in reducing flood risk, and how do antecedent conditions affect flood risk and NFM effectiveness? In particular, we seek to assess the applicability and utility of environmental tracers in providing the empirical evidence required for continued ‘buy-in’ to NFM techniques, and a novel tool in monitoring NFM effectiveness.

The project will be predominantly field based in catchments throughout the Pennines where NFM measures are currently in the planning process. The student will design and test environmental tracer experiments to quantify catchment hydrology and subsequent runoff generation to allow storm hydrograph determination under a number of rainfall scenarios. The student will be involved in the design and implementation of a number of NFM measures and later assessment of their effect on storm hydrology. This primary research will be contextualised using a number of model scenarios in addition to experimental observation. Coupling of experimental and observational data using novel tracer techniques in this manner will allow, for the first time, significant new insights into the potential for NFM techniques in managing flood risk in the UK and world-wide.

For further information, please see http://www.nercdtp.leeds.ac.uk/projects/index.php?id=534 or contact Dr Megan Klaar ([Email Address Removed])