Dez Dam as one of the largest dams of the Middle East has strategic role in development of Khuzestan Plain. Considering dry and semidry climate and subdesert climate of some cities of Khuzestan Province and also due to location of this dam in downstream of sub basins with relatively high sediment yield which caused loss of some useful capacity of tank in years following construction,importance of the present study increases. The present study has been conducted in upstream drainage basin of Dez Dam with area GagingStations for regional analysis of the suspended load and also determination of the sediment yield homogenous regions. In this study, base maps and physiographical, climatic and hydrological characteristics affecting production and carriage of sediment relating to each one of the subbasins were prepared with GIS techniques. Then, relationship between production of special daily suspended load and independent variables with statistical analyses, clustering and multivariate regression. Results showed that Vanaee, Afravandeh(Biatoon), Dokhaharan, Darehtakht, Drorood, Chamchit and Keshvar sub basins were included in the first homogenous group and SepidDasht, Tang Panj(Sezar), Tang Panj(Bakhtiari) and Telezang were included in the second homogenous group. Regression results showed the precipitation factor as the most important factor in production of suspended load of sub basins. To study priority of specific sediment yield for making decisions about prevention of water and soil, sub basins ending to Darehtakht, Dorood and Afravandeh stations had the highest sediment yield intensity in surface area.
