Erosion and sediment transport processes in Mediterranean mountain basins

Soil erosion and sediment production is a major environmental problem in the World, and especially in Mediterranean countries which are characterized by a harsh climate and a historical human pressure on the land. In a context of current and foreseen climate and land use change, our ability to predict the effects of these changes on soil erosion and on water quantity and quality become of great importance. A significant research effort has been made on the subject in the last two or three decades, based both in empirical observations from experimental field setups or in the use of simulation models. However, our understanding of some key processes is still poor, especially under a multi-scale perspective. This encourages the need for further empirical and modelling studies. In this paper, a review of the problem is made and some results are shown from studies in the Spanish Pyrenees. These results are followed by a discussion of several important research questions regarding the use of field experiments and simulation models.