The development of land quality indicators for soil degradation by water erosion

The paper describes a proposed methodology for estimating water erosion ris k for large areas. The estimates are based on a one-dimensional hydrologica l balance and a physically based sediment transport model. Estimates of ris k associated with a given storm amount are integrated over the frequency di stribution of daily rainfalls to provide a properly weighted estimate of th e average annual risk. Soil factors are estimated from textural classes usi ng qualitative pedo-transfer functions. Climatic data are taken from interp olated gridded data. Topographic data are taken from global or local DEMs. The estimates are for sediment delivery to stream channels. The method has been applied to provide a preliminary estimate for France at a resolution o f 250 m, and could be applied globally at a resolution of 1 km. (C) 2000 Pu blished by Elsevier Science B.V.