Dinevar Basin Flood Zoning Relying on the Geomorphologic Characteristics

The study of runoff as a destructive phenomenon and meanwhile very important from the viewpoint of application is very useful. On the other hand, the recognition the area susceptible to produce flood and a program for it’s harness need a multi- dimensional study of the factors which effect flood. This study has been done on Dinevar River for the same reason. First the regional watering curve of Dinevar basin was drown using the annual maximum discharge of 10 hydrology stations to estimate the annual maximum discharge of four Dinevar sub-basins. Secondly, by overlaying of fourteen factors as information layers in GIS, the Dinevar basin has been divided to 5 zones containing the areas with high, relatively high, intermediate, relatively low and low classes. These layers efficient in the forming of runoffs were slope, litho logy, geomorphology, land use, hypsometer, slope aspect, the length of first grade flood channel in litho logy, the length of second grade flood channel in litho logy, the number of first grade flood channel in litho logy, the number of second grade flood channel in litho logy, the length of first grade flood channel in geomorphology, the length of second grade flood channel in geomorphology, the number of first grade flood channel in geomorphology, and the number of second grade flood channel in geomorphology. Result shows that although the slope and lito logy are important factors in Dinevar flood, the geomorphologic structure of Dinevar is the main reason of Dinevar River. In other words, the hogback structure with steepness and impermeable slope is the reason of Dinevar flood. This characteristic causes 35% of Dinevar land have high to relatively high talent and 50% intermediate talent in flood.