Urban Flood Susceptibility Assessment of Central Districts of Van Province, Turkey, Using Geographic Information System (gis)-Based Multi Criteria Decision Analysis (Mcda)

Abstract

Van (Turkey) is one of the easily affected cities in the flooding. According to the latest 60-year statistical data, a total of 166 flood events were occurred in Van province and its districts. The most important reason for the flooding is the impermeable cover of residential areas and poor substructure systems within heavy rainfall in the spring which ground water level is close to the surface due to melting of snow. The scope of this study is to evaluate the flood susceptibility of the central district of Van, using multi-criteria decision analysis (CPL), and geographic information systems (GIS).The susceptibility model developed in this study contains six different factors. These are: lithology, the depth of groundwater table, distance to the discharge channels, slope, elevation (above mean sea level) and land-use. The susceptibility assessment is conducted by using a comparison matrix where all identified criteria of GIS layers are compared against each other. The acceptability and reliability of the model was determined using historical events. All of these events plotted over the model showed that there is a remarkable coincidence with high susceptibility areas. The flood susceptibility model shows that İpekyolu, central district of Van city, has much more flood hazard potential than those of other districts. High susceptibility to flooding in the study area is mainly related with flat terrain features so that the area has a low slope angle, impermeable lithology and the presence of urban stream channels with poor maintenance plan. Therefore, in order to prevent the possible flooding, site planning, improving the stream beds and substructure systems should be effectively integrated in potential areas. © 2016, Hacettepe Universitesi Yerbilmleri. All Rights Reserved.