Abstract

The relative magnitude of sediment output from different types of storm for analysis of long-term sediment yield is based on data from a 15-year sediment monitoring program at Nahal (Wadi) Eshtemoa, Northern Negev Desert, Israel. In this paper, the dual geomorphologic response of the semi-arid Eshtemoa catchment to storm-type is shown through an analysis of: (1) first flush behaviour and (2) flood event suspended sediment yield. Usually, convectional storms in autumn and spring periods produce short-lived flash floods, which are typical of an arid zone rainfall-runoff response. In contrast, winter frontal storms produce prolonged floods that are more akin to the runoff events of more humid areas. Implications of the balance between the two type-storms for the prediction of catchment suspended sediment yield and, hence, reservoir storage capacity are explored.

Keywords: suspended sediment, sediment yield, flash flood, semi-desert, arid zone, dryland