Determination of critical flood intervals using GIS and RS in southern Kerman province

Flooding is a very common natural hazard and can easily cause fatal accidents and economic losses. This study investigates the critical flood intervals in the Hamoun-Jazmourian catchment in the periods of 1992 and 2016 using statistical analysis of hydrometric and meteorological data, hierarchical analysis process (AHP) and fuzzy logic methods, and processing of satellite images. In order to produce flood risk maps, 14 infulencing layers including runoff curve number (CN), altitude, slope, aspect, topographic curvature, drainage density, distance from canals, geology, vegetation, land use, rainfall, topographic moisture index, flow power index and soil type were prepared in Arc GIS and SAGA GIS software environments. In order to obtain the CN map, the soil texture map and then the hydrological groups map were prepared based on the US Soil Conservation Service method. Finally, the combination of soil hydrology groups and land use mappedrunoff curve number for catchment. Prioirity rank of layers were calculated based on pairwise comparisons using AHP approach in Expert Choice software. Each layer was fuzzified in Arc GIS and the obtained weights were multiplied with them. Finally, by combining the 14 layers together based on weighted linear combination mathod, flood risk map was produced. In order to produce control data, Landsat satellite images before and after the flood were used and the AWEI water index was applied to identify the flooded areas. These areas were located around the Hamoun-Jazmourian zone and areas close to the main waterways. According to the results, the gamma layer with 77,17% had the most similarity with flooded areas based on satellite images. Also, statical analysis of data from hydrometric station using SMADA software indicated that the dominant statistical distribution at manystations were obtained from Pearson type and discharge was calculated with a 200 year return period. The results of correlation in SPSS showed that peak discharge was highly correlated with basin area, soil type and rainfall. Also the linear regression with Enter method and Stepwise method resulted in R2 of 0,67 and 0,53, respectively.

Determination of critical flood intervals using GIS and RS in southern Kerman province Keywords:

Landsat Satellite Images , Analytical Hierarchy Process , AWEI Index , Flood Regional Analysis