How does the incidence and scale of flooding impact on river stability?

1. Indicative title of the topic area How does the incidence and scale of flooding impact on river stability? 2. Context / rationale / why is this study important? This
Ph.D will research into how flooding affects the stability of rivers. Floods occurs in different incidences and magnitudes, affecting river stability by combining a
series of processes, such as sediment transport, to change channel morphology. Localised sediment transport in rivers can have increased negative effects on
urban areas when in conjunction with greater incidence and magnitudes of floods. By investigating how incidence and magnitudes of floods effect sediment
transport, we can assess river stability. Currently, sediment prediction through river systems are inaccurate, where the bedload flux measurements are orders of
magnitude higher than observations made, which can have consequences when validating numerical modelling. Climate change is predicted to increase flooding
incidence and magnitude due to increased rainfall across higher latitude areas, therefore flooding events should be analysed for different duration, frequencies
and multiple events, as they are under researched in current literature. It is essential to understand how flooding affects river stability; in order to analyse river
stability, and how this changes, to limit flooding affects, and potentially the damage caused. 3. Literature review and methodologies Storm Desmond of winter
2015-16, affected almost 5 million people (Environment Agency, 2009) and the damage was estimated to cost between £5-5.8 billion (KPMG, 2015). Showing
that flooding poses a major risk to both the economy and the population of the UK. The risk is set to increase, as climate change has been attributed to a 30%
increase in monthly rainfall, causing more frequent and intense storms increasing the incidence and magnitude of flooding (Burrel et al, 2007) (Committee on
climate change, 2016). This could double the current peak river flows in some English regions by 2070 (Defra Flood Risk Assessment, 2016); similar
conclusions by the IPCC suggests an increase in flood regime and other peak events around the UK (IPCC, 2007). There is, however, a lack of detailed
information on the effect on local hydrology, suggesting more empirical data should be gathered to develop new strategies to understand the effects of flooding
on river stability (Burrel et al, 2007). Sedimentation processes generating high fluxes of coarse sediment, up to gravel sized particles in upland channels during
flood events, contributing to overall flood damage. Elevated stream flows modify the channel morphology, causing water to flow outside the river network and
potentially into urban areas (Rickenmann, Badoux, and Hunzinger, 2015). Consequently, coupling sediment transport with increased flow into vulnerable areas,
investigating bed stability is essential to prevent disaster and improve socio-economic resilience. Suitable field research methods are dependent on the research
project objectives, however, the conditions and characteristics of the site will ultimately determine the best or most efficient techniques to use. Direct
measurements of the bedload can be more accurate than indirect formulae (Schwendel, Death, and Fuller, 2010), however, bedload traps interfere with the
measurement continuity, requiring sample period adjustments, consequently producing uncertainties of 50% (Wilcock, 2001). Recent developments in
terrestrial laser scanners (TLS) have improved our perspective on the processes impacting on rivers (Brasington, Vericat, and Rychkov, 2012). TLS are used to
monitor surface changes by producing high-resolution digital elevation models. Subject to some ambiguity in position measurement, errors can cause significant
problems as small uncertainties in elevation can produce large volume errors, extrapolated over large complex areas (Schurch et al., 2011). Gravel beds vary
spatially, so to understand sedimentati