Soil Erosion Mapping and Erosion Risk Assessment in North Wales - a Geomorphological Approach

Abstract

This study aims to survey and map the soil erosion of 'A Site of Special Scientific Interest' (Eglwyseg Mountain) in North Wales, and to develop a simple but comprehensive model for erosion classification and prediction of erosion potential. Erosion features are identified and mapped following interpretation of aerial photographs and field observations. A multiplicative erosion assessment model is employed on the basis of present erosion severity, soil erodibility, vegetation cover, and slope gradient and form. The model is used to classify the study area into various erosion classes ranging from slight erosion to very severe erosion. From correlation tests and field evidence, vegetation is considered to be the most important parameter in the soil erosion system. Attention is directed towards biotic pressure as the main cause for a reduction in vegetation cover. Potential erosion is determined by assessing the difference between the present and the acceptable minimum percentage cover, and is compared to present erosion severity assessed in the field.