Quantification of the impact of changing vegetation on hillslope sediment transport

 

Supervisor(s): Dr Stuart Grieve (s.grieve@qmul.ac.uk QMUL Geography, Emily Lines (QMUL Geography)

Project description

Hillslope sediment transport exists on a continuum from the gradual downslope motion of particles, termed soil creep, to catastrophic shallow landslides and debris flows. In upland, forested landscapes trees and other vegetation play a vital role in the modulation of these processes, with root growth and tree throw driving soil creep, whilst reducing landslide hazard through an increase in soil cohesion. There is growing evidence that the structure and dynamics of forests are changing as a consequence of climate change, alongside changes to forest structure driven by changing forest management practices. Consequently, it has become increasingly important to understand the implications these large scale changes in forests will have on both fine scale sediment transport and slope stability. 

This project will integrate forest structural analysis using terrestrial laser scanning (TLS), with topographic analysis from airborne LiDAR and ecological and landscape evolution modelling to constrain the key factors which influence hillslope sediment transport at short (minutes to hours) to long (millennial) timescales. The analysis of TLS data to quantify tree structural properties such as branching, leaf area, crown density, biomass and neighbourhood interactions, will build on techniques developed by current PhD student Harry Owen (cohort 3). Analysis of airborne LiDAR data will be performed using LSDTopoTools (http://LSDTopoTools.github.io), a state of the art software package developed at QMUL in collaboration with colleagues from Edinburgh, Glasgow and Durham Universities. Full training in all of these methods, alongside opportunities to collaborate with other users of LSDTopoTools, will be provided to the successful student. 

Policy Impact of Research

In the UK, a significant amount of forested land lies upslope of infrastructure (rail lines, roads, power lines), and it is therefore vital to understand the implications of changing forest dynamics on slope stability. 

How to apply 

Opportunities for funding include London NERC DTP and QMUL Principal’s Postgraduate Research Studentships. For further information about the project, eligibility and future application deadlines in 2019/20, please contact Dr Stuart Grieve.