HEC-RAS and GIS Based Flood Hazard Analysis: A Case Study of Muş Basin

Abstract

Urbanisation, uncontrolled land use, infrastructure and engineering practices that are inconsistent with basin characteristics, and settlement planning that does not consider flood risk alter natural drainage systems, thereby obstructing surface runoff and increasing flood hazards. Due to topography and climatic conditions that intensify flow processes, Eastern Anatolia is, after the Aegean and Eastern Black Sea regions, one of the regions where flood events are frequently observed. The Muş Basin, located in the Eastern Anatolia Region and covering an area of 3.482 km², is one of Turkey's plains most frequently affected by floods. In this study, the flood threat in the Muş Basin was simulated under various discharge scenarios using measured flow data from previous years, a 5-m-resolution Digital Terrain Model (DTM), and the HEC-RAS 1B modelling system. The results indicate that flood depth and flow velocity exhibit significant spatial variability across the basin. In particular, high flood risk has been identified in the vicinity of the settlements of Sungu, Yeroluk, Mercimekkale, and Muratgören, and these findings are spatially consistent with flood events recorded in previous years