Determination of Basin's Physiographic Characteristics Derived from the ASTER Digital Elevation Model (Case Study: The KabudRahang Plain, Hamedan, IRAN)

Elevation is one of the main sources of information required for the determination of physiographic characteristics of a basin. Digital Elevation model (DEM) is one of the products derived from the Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) sensor satellite images. The objective of this study is the determination of physiographic characteristics of basins using ASTER DEM. Thus, The KabudRahang Plain KRP was selected as the study area, which is a part of 3448 km2 of Gharechai Catchment Basin in the northern part of The Province of Hamedan. In order to evaluate the outputs, comparison was made with values provided by the Office of Regional Water Studies of Hamedan, which were extracted from an aerial imagery of National Cartographic Center, and the digital elevation model derived from the SRTM sensor images and the Geographic Information System methods. To achieve the study objectives, Firstly, the channel network, including flow and cumulative flow direction was determined, using the ASTER derived DEM. Then The KPR Basin was studied and the rivers were ranked. Finally, the physiographic characteristics of the basin were extracted. The results show that the basin area, perimeter, and length were 3410.43 km2, 406.34 km, and 112.82 km, with a relative error of 1.09, 5.82, and 8.28 percent, respectively. Furthermore, the basin shape factor was calculated using the Horton, Gravelius, Miller and Schumm methods, which resulted in 0.267, 1.94, 0.259 and 0.584 values, respectively. The time of concentration values were 13.33, 4.86, 6.91, 46.53 and 148.57 hours calculated using the Kirpich, Kerby- Hathaway, Bransby Williams, Carter, and Ventura methods, respectively.