A study of spatial variability of soil loss with high resolution DEMs: A case study of a sloping olive grove in southern Spain

Land degradation worldwide over several centuries has become a serious problem. This phenomenon has been accentuated in agricultural areas, where the amount of topsoil loss creates a gradual loss of farmland productivity. Ploughing is responsible for tillage erosion which causes more soil movement than natural soil creepage. In fact sediment transport is more rapid using heavy machinery than with primitive ploughs. The main aim of our research is to monitor, in detail, the sediment deposition phenomenon of eroded soil. Here the role of high resolution DEMs is essential. We develop a DEM generated from field measurements taken by GPS. The high spatial density of these measurements allows us to generate DEMs of high resolution: cell sizes of 0.5, 1 and 1.5 m. Three zones of different area are used in order to analyse the scale effects. In this study we assess precise models that represent a soil redistribution phenomenon.