Comparison of results of flood hazard zoning using AHP and ANP methods in GIS environment: A case study in Ardabil province, Iran

Zoning of flood hazards in a dam catchment plays an essential role in water resources planning and management. In the present study, nine lithogenic and anthropogenic parameters including slope, elevation, curve number, distance to river, rainfall, geology, soil texture, Normalized Difference Vegetation Index (NDVI) and land use are used to achieve a flood hazard map in downstream of Sabalan dam basin in Ardabil province, Iran. After categorizing the criteria, the layers were weighted by two multi-criteria decision making (MCDM) methods including analytic hierarchy process (AHP), and analytic network process (ANP). The results showed that among the factors affecting flood formation in the study basin by AHP method were the elevation and slope factors with the weights of 0.31 and 0.18 respectively, have the highest effect; however, curve number and distance to river factors with the weights of 0.04 and 0.02 have the lowest effect. Similarly, in the ANP method, the elevation and slope factors with the weights of 0.30 and 0.21 respectively, have the highest effect and the curve number and distance to river factors with the weights of 0.02 and 0.006 have the lowest impact on flood hazard potential in the study area. The results obtained in this study can be useful in achieving sustainable management of water resources.