Suspended sediment concentration and its variation with water discharge in a dryland ephemeral channel, northern Negev, Israel

Relations between suspended sediment concentration and water discharge during flash floods in an ephemeral stream of the northern Negev are analysed. Water samples were obtained with a pre-programmed sampler. The mean suspended sediment concentration measured during 6 years of monitoring was 34,000 mg l−1, with individual flood maxima in the range 21,000–229,000 mg l−1. Regression of suspended sediment concentration on water discharge takes the form SSC=104•41Q0•42. However, only 50% of the variance in suspended sediment concentration is explained by variations in discharge. This indicates that changes in sediment supply and variations in the importance of source areas are also significant in this semi-arid water catchment