Flood Modeling on Koya Catchment Area Using Hyfran, Web Map Service, and HEC-RAS Software

In this research, The boundaries of the Koya catchment area have been delineated, and valley paths in region were drawn by using Water Modeling System (WMS) software, Analysis morphometric information indicated that characteristics watersheds contribute to floods. average surface runoff depth depends on curve number values are determined based types soil cover class according Harmonized World Soil Database HWSD software indicates study Group B silt loam, results obtained also show potential for varies with land use characteristics. Also, value (CN) was be 71. hydrological modeling performed HEC-HMS program simulates process rainfall SCS model. A flood hydrograph constructed at outlet floodplain delineation verified HEC-RAS software. 100-year return period could Reach critical areas such as urban area, agricultural residential areas. indicate there suitable sites constructing small dams ponds water harvesting.