The influence of surface properties on flow and erosion processes on debris covered slopes in an arid area

A study aiming to obtain quantitative data on the processes of slope runoff and erosion under arid conditions and relate them to rain and surface properties, was conducted near Elat, in southern Israel. Slope-channel relations, with regard to runoff and sediment transport, were also analysed. Data were obtained by means of three overland flow collectors, two rain recorders and one hydrometric station. The research was conducted over one rain season, during which a single channel flow and five overland flow events occurred. The results lead to the following main conclusions: 1) For a small drainage basin, the threshold values for slopes and channel flow are 3 mm and 5 mm per day, respectively; 2) No clear relation exists between the slope angle and slope runoff and an inverse relation exists between slope angle and slope erosion.