Modelling the impacts of climate change on future rates of soil erosion in Northern Ireland

• Main Author: Mullan, D. J.
• Published: Queen's University Belfast 2013
• Subjects: 631.45
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.580104

Given the potential for climate change to increase soil erosion and its associated adverse impacts, modelling future rates of erosion is a crucial step in its assessment as a potential future environmental problem, and as a basis to help advise future soil conservation strategies. Despite the wide range of previous modelling studies, iri the majority of cases limitations are apparent with respect to their treatment of the direct impacts (climate change), and their failure to factor in the indirect impacts (changing land use and management). In this study, these limitations are addressed in association with the modelling of future soil erosion rates for six hillslopes in Northern Ireland using the Water Erosion Prediction Project (WEPP) model. The direct impacts are handled using statistical downscaling methods, enabling the generation of site- specific, daily resolution future climate change scenarios, and a simple sensitivity analysis approach is employed to investigate the previously unstudied impacts of sub-daily rainfall intensity changes. Finally, the frequently neglected indirect impacts of changing land use and management are examined using a scenarios-based approach. Results indicate a mix of soil erosion increases and decreases, depending on which scenarios are considered. Downscaled climate change projections in isolation generally result in erosion decreases, whereas large increases are projected when land use is changed to a row crop which requires annual tillage, and / or where large changes in sub-daily rainfall intensity are applied. The off-site impacts of erosion are likely to become a more considerable environmental issue with respect to water quality and 'muddy flooding' under a wide range of future scenarios. The overall findings illustrate the potential for increased soil erosion under future climate change, and illuminate the need to address key limitations in previous studies with respect to the treatment of both the direct and indirect impacts of climate change.