Investigating moisture dynamics in vegetated soil using novel geophysical tools

Planted areas are an important aspect of managing urban surface water and shallow geotechnical assets. However, root water uptake and the impact on soil hydrology and slope stability are poorly understood in heterogeneous soils and under extreme climatic conditions. To better understand the influence of vegetation on soil water dynamics in geotechnical infrastructure, Electrical Resistivity Tomography (ERT) will be used. ERT is a non-invasive tool for volumetrically measuring and imaging subsurface soil moisture dynamics. Through the various applications of ERT, it is the goal of this research to improve upon the current understanding of vegetation driven soil moisture movement, in order to better analyse slope stability and inform urban planning and development.

The aim of this research is to determine the impact of vegetation on the soil hydrological performance of engineered slope fill and SuDS (Sustainable Urban Drainage Systems) using ERT.

The objectives of this research are to:
1. Critically assess the interactions between vegetation, water, and soil.
2. Demonstrate the suitability of ERT for quantifying transient soil moisture changes in granular drainage substrate and clay-based engineered fill.
3. Develop and appraise the use of ERT as a non-invasive tool to investigate vegetation-driven moisture movement.
4. Determine the range and extent of plant driven soil hydrological changes in granular drainage substrate and clay-based engineered fill.
5. Establish using ERT, the transient soil moisture variability in vegetated soils at field scale under natural and simulated atmospheric conditions