Designing to the spatial data infrastructure for disaster management-preparation phase, susceptible areas for flooding and overflow: example of Istanbul European site

National Spatial Data Infrastructure (NSDI), from underground structure, such as buildings in the surface of the object to the sky, covers the basic points that should be used in many projects. Every time we are confronted with disasters on our planet, data which is required for disaster management, can be shared very easily and effectively in the internet environment using up-to-date technology. When Geographic Information Systems (GIS) analysis tools and NSDI are integrated, the solutions can be produced for almost every phase of disaster management.In this study, the preparation phase of disaster management has been approached with a NSDI-GIS vision and an example of determination of the susceptibility of the flood and overflow. Flood and overflow susceptible areas of the European side of Istanbul; were determined by the the GIS - Multi-Criteria Decision Analysis (MCDA) method. Criteria that affect the flood and overflow were defined as; rainfall, elevation, slope, aspect, drainage density and size of sub-basins. Digital elevation data, data of the details for drainage, rainfall data, data for hydrologic soil groups, land cover data, boundary data (provincial boundary, land boundary, lake boundary), current orthophotos, flood and overflow data that is produced in accordance with rational method have been used for preparing the criteria layers.SCS-CN (US Soil Conservation Service Curve Number) empirical model developed by SDA (United States Department of Agriculture) - which is one of the precipitation-flow models - was used in order to create flow layer. Criteria layers prepared were normalized according to the Linear Scale Transformation - The Maximum Value method.AHP (Analytic Hierarchy Process) is used in stage of decision analysis of MCDA.Pair wise comparison method was applied in order to determine relative weights of the each criteria in the scope of the AHP. Consistency ratio was calculated to determine whether the comparisons, consistent or inconsistent and it was understood that they were consistent. Susceptibility layer was created via synthesizing the weights with normalized criteria layers. Susceptibility areas for flood and overflow were defined in MCDA after susceptibility layer was classified using natural break method.Susceptibility areas obtained with MCDA were compared with flood and overflow areas defined by rational method. Susceptibility areas are showed similarity with a ratio of %97. Data model design was conducted for NSDI by evaluating data used and analysis.