EVOLUTION OF THE CONCENTRATIONS AND THE SEDIMENT DISCHARGE ACCORDING TO THE LIQUID FLOWS IN THE WATERSHED OF THE WADI BELLAH TIPAZA

Abstract

The sediment transport is its importance, a major problem (agricultural land, siltation of selected …). In Algeria, it is measured in the watershed gauging stations for almost all episodes of flow. Generally, it is limited to the suspension flow.

Our study is based on the watershed of wadi Bellah, Algeria. It is located in semi-arid. The data acquired by the station Pont RN 11 (sediment concentrations C (g/l) and liquid flow rates Q_l (m³/s)) and used for quantification of daily transport in suspension were analyzed to determine their reliability and validity based on the evolution of Q_s = C.Q_l and Q_l.

This data is performed by the National Water Resources Agency (ANRH, Algeria) between 1974 and 1999. Generally, best results are obtained by an equation of type: Q_s = a.Q_l^b with, Q_s sediment discharge (Kg/s), Q_l, average daily flow (m³/s) and a, b are empirical coefficients. And the results show that the value of the average specific degradation is comparable to that found for other regions in similar hydrological regime.