Landscape Change, Soil Erosion, and Runoff Risk in the Lower Rother Catchment, West Sussex

: Evaluating Data-Driven GIS Applications for Sustainable Agri-Environmental Policy

Abstract

The lower Rother catchment in West Sussex, southern England, has a long rural heritage but experiences significant contemporary soil erosion and runoff issues driven by agriculture, degrading land and water quality and generating substantial financial costs to land managers. These challenges have arisen as a result of long-term land management practices, coupled with the increasing intensification of modern farming activities and climate change, necessitating effective, evidence- based strategies to support sustainable agri-environmental policy-making. This doctoral research addresses these problems by analysing historical landscape changes, assessing soil erosion and runoff risks, and exploring data-driven GIS tools to inform targeted policy interventions. A comprehensive investigation of land use/land cover changes since the mid-19th century was conducted using tithe survey maps and remote sensing data, revealing substantial shifts, including a rise in improved grassland and woodland and a sharp decline in arable land and semi-natural grassland. The established SCIMAP framework was applied to simulate erosion and runoff risk under various foresight land cover and climate simulations. The analysis revealed several notable areas of persistent high risk across the catchment, particularly in the northern River Rother floodplain, which were compounded by arable expansion scenarios. A sediment accumulation risk model was developed to optimise the placement of vegetated buffer strips at the farm scale. By comparing the suitability of current and historical field boundaries close to high-risk sites, the model outputs provide a practical framework for implementing nature-based solutions to mitigate soil loss from agricultural fields. These insights underscore the value of integrating historical data with GIS-based modelling to design strategies that balance soil conservation, agricultural productivity, and cultural heritage preservation. Overall, the research highlights the effectiveness of data-driven methods in examining landscape change and sediment dynamics and demonstrates their valuable application for policymakers to guide decision-making.

Date of Award	19 May 2025
Original language	English
Awarding Institution	University of Portsmouth
Supervisor	Harold Lovell (Supervisor) & Philip Soar (Supervisor)