Malaysian Journal of Geosciences (MJG)

In recent decade (century), variation of streamflow and sediment load in different catchments has received considerable attention due to the complex pattern and trends of the river behavior. Detailed investigations were achieved on the changes of streamflow and sediment concentration through hydro-climatic conditions. Two fundamental questions about the utility of the sediment rating curve technique in the assessment of sediment load in relation to geomorphic conditions were discussed in the present paper: (i) how is the efficiency of the parameters, a and b, to characterize trends in the data?, and (ii) what are the possible relationships of the sediment rating parameters and the hydroclimatic events? For this reason, the present study attempts to examine the relationship of sediment transport and streamflow recorded at three gauging stations in the Seybouse basin in relation to their controls at the annual and monthly levels. The rating parameters obtained from the power functions of sediment discharge and water discharge data were investigated and associated with rainfall and runoff of the selected basins in order to characterize the trends of the parameters a and b at different river water and sediment supply conditions. The relationship between the constant a and the hydraulicity, during humid years, is solely high in the Bouhamdane. The association of a and rainfall includes mainly Mellah catchment. The seasonal models of the relationship between sediment yield and water discharge give for the fall and summer, in Bouhamdane catchment, the highest values of the constant a. This reflects the existence of data that are sometimes extreme which lead to a rise of the value of a, whereas the rate of the produced sediment yield is often low during these often dry seasons. It is outlined from the studied models that they cannot be used every in other basins. Also generalize them to any erosion proves to be a doubtful and inadequate operation.