Innovative geomorphic approaches to support better management of flood risk and ecosystem health

Project rationale:
Flood risk is controlled by both the hydrology and the physical shape and behaviour of a river and its floodplain (e.g., river type and behaviour; impacts of artificial modifications). Although hydrological drivers are easily recorded and well understood, how they interact with river behaviour and the impacts of extensive artificial modifications are not. Existing data and tools are limited, vary between UK nations, and require development. This creates a gap in our ability to manage flood risk in future.
To address this gap we need national coverage of geospatial data to understand: (1) existing river attributes and landscape conditions that influence their behaviour (e.g. stream power; sediment flux; valley confinement); and (2) distribution and type of physical modifications. This baseline data can then be used to create tools which characterise how responsive different sections of river are to floods (both now and in the future with climate change), based on the type and extent of anthropogenic modifications and underlying channel characteristics. These data should also be useful to understand more about wider natural riverscape functioning, which additional uses such as catchment-scale scoping for river restoration and understanding the impact of different types of future development.

Methodology:
This PhD will aim to improve our understanding of how flood risk changes due to zones of increased channel adjustment, by building on existing datasets and projects (e.g. Environment Agency’s Channel Sensitivity Project, 2021, Grieg et al., 2006; SEPA, 2021). The work will assess existing river characteristics, behaviour and physical modifications, using these to map geomorphically-controlled flood risk from ‘hot spots’ to ‘cool spots’ across the fluvial network, and develop knowledge and tools to understand the risk better. The anticipated research stages are:

(1) Review existing science and national-scale datasets that are used or could be used to identify zones of geomorphically-controlled flood risk:
(2) Identify scientific and data gaps which need to be filled in order to improve our understanding of geomorphically-controlled flood risk.
(3) Combine literature review findings with existing data to create new maps or tools to map hotspots of river responsiveness, resilience, and geomorphically-controlled flood risk.
(4) Quantify the degree of confidence and uncertainty associated with risk predictions by comparing improved risk predictions with locations of channel adjustment identified from existing geomorphic studies into previous major floods (e.g., Storm Desmond).

The outputs should enable better predictive capabilities, by understanding and improving how geomorphic and landscape processes control flood risk.

References:
Environment Agency, 2021 ‘Understanding river channel sensitivity to geomorphological changes’ Understanding river channel sensitivity to geomorphological changes - GOV.UK >Greig S.M., Richardson R. and Gibson J. (2006). A new impact assessment tool to support river engineering regulatory decisions: SNIFFER Technical Report. Project No. WFD49. A12. Morphological Impact Assessment System (MImAS) - PRAGMO (therrc.co.uk)

SEPA (2021) – Will the river do the work? will-the-river-do-the-work.pdf (sepa.org.uk)