Spatial assessment and analysis of flood risk in desert and desert areas based on the combination of ANP methods and pairwise comparison in GIS environment (Case study of Khorasan Razavi province)

In this study, by combining GIS and multi-criteria decision making systems (MCDM), areas with different degrees of flood risk for sustainable settlement of the population in each of the cities of Khorasan Razavi province have been identified. For this purpose, first 6 effective parameter data including maximum discharge with 2, 3, 5, 10, 25, 50, 100 and 200 year return periods obtained from HEC-HMS software output, drainage density, land use and Vegetation, CN, slope and permeability of the study area were prepared in GIS software environment. Then, using ANP method and pairwise comparison, the weight of each criterion and the weight of the classes of each layer in Super Decision software were calculated, respectively. Then, using GIS software analysis functions, the whole range was zoned for each of the specified criteria. It was prepared a lot until the flood. The results showed that the area of ​​cities that are exposed to very high floods and the results of flood risk zoning with a return period of 2 years in the whole province showed that more than 86% of areas with low and very low floods, 2 12% of the areas are moderate and 1.8% are high in terms of flooding. While the results of flood zone in the 200-year return period showed that 41.3% low flood, 31.4% moderate flood, 13.3% high flood and 14.1% very high flood in the whole province.