رسوب شناسي حوضه آبريز سد سنگرد سبزوار

Sedimentological study of the Sangerd drainge basin in Sabzevar

The Sangerd drainage basin is located in central part of Khorasan Province in arid to semiarid climate conditions and consists of three subbasins. Structurally, the study area is a part of Central Iran zone, and is compsed of Mesozoic and Cenozoic rocks. The river channels are mainly single with sandy gravelly bedload. The presence of shale and marl as well as seasonal rainfall in the study area, causes the strong erosion. Based on sedimentological studies, 9 lithofacies have been identified. The majority of sediments are sandy gravel (sG) but in downstream they change to gravelly muddy sand (gmS). Geologically, the presence of less resistance sedimentary rocks causes to produce a lots of sediments that can fill Sangerd reservoir very quickly. Therefor, we suggest by changing the hydrulic condition of channels can decrease the erosion and sediment transpot