Using GIS software for modeling stream basins

Floods are one of the natural disasters that can cause significant loss of life. The growth of settlements in flood areas, faulty land use and climate change causes the negative effects of floods to increase. Today, the risk analysis of natural disasters and determination of flood areas can be made more easily and precisely thanks to Geographical Information Systems (GIS). In this thesis, Tohma basin was chosen as the study area. In the first stage of the study, some basin parameters (precipitation, slope, view, soil, geology, land use and distance to rivers) of Tohma basin were determined using ArcGIS software. In the second stage of the study, Flood risk maps were created by using Analytical Hierarchy Process (AHP) and Fuzzy Logic Hierarchy Method (BAHP) methods from Multi Criteria Decision Making Methods (MDMM). In both methods, it was observed that the mean weight of basin parameters and the flood risk maps of the basin were close to each other. In addition, flood risk zones were classified in the study area, from high to low. KEYWORDS: Basin, Geographical Information Systems (GIS), Analytical Hierarchy Process (AHP), Fuzzy Logic Hierarchy Method (BAHP), MDMM