Flood inundation mapping by GIS and a hydraulic model (hec ras): a case study of Akarcay Bolvadin subbasin, in Turkey

Abstract

In this study, it is aimed to constitute flood inundation maps for Akarcay Bolvadin Subbasin. Topographic data of study area is defined for hydraulic model by sectioning along the river on Digital Elevation Model (DEM) which is created by ArcGIS, a Geographical Information System (GIS) software. It is used HEC RAS software as hydraulic model. Data migration between ArcGIS and HEC RAS is provided by using an intermediate module, HEC GeoRAS. After required geometrical and hydraulic structure data are constituted, flood inundation maps are obtained by inputting flow data into the model. Flow data is calculated by Fuller Method for various recurrence intervals. In consequence of hydraulic modelling, flood depth and velocity values are also acquired. The areas at flooding risk are determined by taking account of flood inundation, depth and velocity data. And it is given several suggestions for take due precautions in these areas.