| Abstract: | To assess the effects of climate change on soil erosion we need to model changes in rate, frequency and extent of erosion. Present day rates of soil erosion for agricultural land in England and Wales are known from a national monitoring scheme and also from a local one. The latter, for the South Downs, covers a seven-year period and includes climatic data. This shows a strong correlation between total erosion and a Rainfall Index. The availability of these databases allows us to use existing models such as EPIC and an Expert System to predict erosion rates for postulated warmer and wetter (winter) conditions. EPIC is particularly suitable for specific sites where detailed data exists and crop yield implications can also be modelled. A rule-based Expert System approach allows us to examine erosion rates at a different scale across the landscape. We postulate that water erosion rates on arable land in the lowlands will increase markedly in severity, frequency and extent especially if land use changes. In the uplands predicted climatic warming suggests a longer growing season and fewer frosts: these may lead to a decrease in erosion of overgrazed eroding slopes. Increases in erosion rates are not inevitable if policy decisions are taken and implemented in good time. |
