Suspended sediment transport in flash floods of the semiarid northern Negev, Israel

Our aim is to provide insight into various suspended sediment transport phenomena of upland ephemeral streams in a semiarid environment. Information about suspended sediment concentration is derived with the help of a programmable pump sampler and the continuous record of a turbidity sensor. Suspended sediment concentrations are high; the mean during six years of measurements was 34 000 mg l^-1 and regression of suspended sediment concentration on water discharge takes the form SSC = 10^4.41 Q^0.42 During individual flash floods, the suspended sediment-water discharge relation may be hysteretic (clockwise or counterclockwise) and/or monotonic. In spite of complicated intra-event behaviour, there is a good, deterministic (R² > 0.9) relation between total suspended sediment yield and flood volume.