Flood analysis of Munzur river tributaries using HEC-RAS and ARCGIS

Floods are among the most common types of natural disasters worldwide, causing significant loss of life and property while also adversely affecting social and economic activities in the affected regions. The impacts of floods are not limited to physical damage; even individuals who are not directly affected by the event may experience psychological and sociological trauma as a result of environmental changes. Therefore, floods should be considered multidimensional disasters that require not only engineering-based solutions but also an assessment of their social implications. In this study, the areas located within the zoning boundaries of Aktuluk Town in the Mazgirt district of Tunceli Province identified as a flood-prone regions were examined. The T1, T2, and T3 tributaries, which connect to the Munzur River and remain dry for most of the year, were analyzed. Geographical and topographical data related to these streams were evaluated using ArcGIS, one of the Geographic Information Systems (GIS) technologies. Digital Elevation Models (DEM), slope, and flow direction analyses were conducted through ArcGIS, and flood inundation areas were mapped accordingly. The spatial data obtained from these analyses were then integrated into the HEC-RAS (Hydrologic Engineering Center – River Analysis System) software to perform one- and two dimensional flood modeling. Within the scope of the modeling process, the carrying capacities of the existing streambeds, channel cross-sections, and structural hydraulic elements such as culverts, bridges, and weirs were examined. Simulation results were used to evaluate the adequacy of these structures under various flood discharges and to identify critical areas at risk of flooding. Furthermore, sediment transport from the upstream basin and potential blockages were considered in order to analyze possible flood scenarios. This study aims to contribute to planning, design, and engineering practices intended to prevent floods or mitigate their impacts. The findings provide a scientific data source that can assist local authorities in identifying hazardous areas in advance, developing disaster management strategies, and implementing preventive measures particularly for addressing landslides triggered by flood events in the region.