The route that water and sediment take as they move through catchments is an essential hydrological characteristic: the length of flow paths controls the magnitude and frequency of flood events, patterns of erosion and deposition, and transport of nutrients and pollutants. Flow paths are fundamentally controlled by landscape topography: the differences between hydrological connectivity in different parts of the landscape has been considered (e.g. Lane et al., 2009), but there is currently little understanding of how hydrological connectivity and flood hazard change over long timescales.

This MRes project will use landscape evolution modelling to simulate changing catchment topography through time and its associated controls on the structure of the fluvial network, to understand how flow pathways change over time in different landscapes. The project will analyse the simulated landscape using various connectivity indices, such as the Network Index of hydrological connectivity (Lane et al. 2004) and the Index of Connectivity (Borselli et al. 2008). Following on from this, the project will investigate how changing flow paths in simulated landscape affects the magnitude and frequency of simulated flood events.

Borselli L., Cassi P. and Torri D. 2008: Prolegomena to sediment and flow connectivity in the landscape: A GIS and field numerical assessment; Catena 75 268–277

Lane, S.N., Brookes, C.J., Kirkby, M.J. and Holden, J. 2004. A network-index based version of TOPMODEL for use with high-resolution digital topographic data. Hydrological Processes, 18, 191-201

Lane S N, Reaney S M and Heathwaite A L 2009: Representation of landscape hydrological connectivity using a topographically-driven surface flow index; Water Resources Research, 45, W08423 doi:10.1029/2008WR007336