Analyzing Sedimentgraph Data in Chehelgazi Watershed Upstream Gheshlagh Dam

Soil erosion and sediment yield from watersheds are among the key limitations to achieve sustainable use of land and to maintain the water quality in water bodies. Studying the soil erosion process and and evaluation of dominant factors on erosion is therefore considered fundamental in watershed management. The accurate measurement of sediment yield using sedimentgraph data is accordingly of major importance. The present research was conducted to analyze sedimentgr-aphs in Chehelgazi Watershed upstream Gheshlagh Dam basin in the Kurdistan province in Iran with an area of 27233 hectare. The hydrographs and sediment graphs of 11 storms from winter 2006 to spring 2007 were investigated. The results revealed that the sediment graphs with average sediment yield of 79.5647.93 tones followed the general trends in corresponding hydrographs. All hydrographs preceed the sedimentgraphs with an average lag of 2.941.04 hours.