Trends in runoff and erosion processes over an arid limestone

Abstract. The study describes an experimental site installed in an arid region for the study of spatial variations in rainfall, runoff and erosion processes along slopes. Data obtained indicate that despite the frequent development of universal overland flow, due to excess rainfall, runoff generated at the upper part of slopes, 60^70 m in length, has little or no chance of reaching the slope base during most rainstorms and thus does not contribute to channel flow. The spatial distribution of areas contributing to channel storm flow was found to be similar to that observed in the humid regions. In both cases the contributing area is limited to a belt extending at the base of the slope area. An analysis of the factors affecting the spatial pattern of runoff development in the arid zone is presented. Suspended sediment data collected indicate that no correlation exists between observed sediment concentrations and runoff rates. Tendances d'écoulement et des processus d'érosion sur une pente de colline aride calcaire, Negev du nord, Israel Résumé. Cette mémoire décrit une location expérimentale installée dans une région aride pour l'étude des variations spatielles de précipitation, écoulement et les processus d'érosion le long des pentes. Les données obtenues indiquent que, en dépit du développement fréquent du ruissellement de surface global, à cause de la précipitation excédentaire, l'écoulement généré sur les parties plus hautes des pentes, 60 à 7