Flood Prioritization Watersheds of the Aras River, Based on Geomorphometric Properties: Case Study Iğdır Province

Abstract

Drainage watershed morphometry plays a major role in terms of understanding flood dynamics. Flood potentials are explained considering the linear, areal, and relief morphometry features of the watersheds. In general, there are number of geomorphometric indices in the description of these features. The formal geometries, geomorphology, geology, and general climate characteristics, etc., which play a decisive role in the flood potential in the watershed, can be determined relatively with morphometric indices. In this study, 35 different river watersheds draining their waters to the Aras, located in the center of Iğdır Province, were examined. Geographic information systems (GIS) and statistical software were chosen to analyze and calculate indices for this research. Flood events occur in these 35 different river watersheds and this study evaluates river watersheds in terms of their flood potential using 14 different indices. In the evaluation of the results obtained, the values that have a high impact on the floods are ranked according to their priorities. These results were evaluated in terms of flood priorities using morphometric analysis and principal component analysis methods. Flood priorities of watersheds, obtained through two different methods, are classified as high, medium, or low priorities. The number of common watersheds, determined based on two different methods, is 8 in river watersheds with "high" priority, 11 in river watersheds with "medium" priority, and 7 in river watersheds with "low" priority. According to these results, it is seen that river watersheds with high priority flood potential correspond to the areas where flood events occurred.