The Effects of Geomorphological Parameters on Products of Sediment in Ghazghanchay Basin (Sub Basin of Hable Rood)

The effects of soil erosion plays a role in incidence of dangerous floods, rapid loading of dams and destruction of farmlands, and prevents the occurrence of floods as well, important measures need to be adopted in order to prevent its store from being loaded. The purpose of the present study was to study the geomorphological problem of the mentioned dam, the role it plays in production of sediment and its effect on Nam Rood Dam in Ghazghinchai Basin, with focus on degree of erosion and the amount of sediment produced. Ghazghinchai Basin is located in south of Central Alborz Mountains, North-Eastern Tehran Province, and is one of the sub-basins of Nam Rood River and covers an area of about 144.235 km2. In order to study the amount of erosion and the sediment produced in the basin under investigation, first the variables effective in erosion were analysed by GIS softwares, through direct observations, field work and indirect observations including satelite images, air photos and climatic and hydrological data. And finally in order to achive our intended purposes such common methods of estimating erosion in sediment the Besyak Model were used. Technique of giving scores and integrating layers were also used to estimate the amount of erosion in basin under investigation. The results show that the annual amount of sediment poduced in the basin is around 14011.24 tons per km2. The findings also indicat that the major proportion of this amount of sediment is produced from the central parts of the basin which lie in the show area with high degree of erosion, as show by the results of our zoning.