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In arid regions, the analysis of wadi morphometric and hydrologic parameters and their interrelationships are fundamental for describing the hydrologic potential efficiency of the watershed and ranking the control variables of the watershed according to their impact on the flood evaluation. In this paper, digital elevation model, geographic information system, hydrological modeling, and multivariate statistical techniques are integrated for the identification and the assessment of the input variables that are used in the evaluation of the flood parameters. For this purpose, factor analysis (FA) and cluster analysis (CA) have been implemented to achieve these goals. To achieve a high accuracy in the hydrological simulation, Hadramaut catchment has been divided into eight sub-catchments. Each sub-catchment has different morphometric characteristics. Twenty-two morphometric and hydrological descriptors have been extracted and evaluated using the aforementioned techniques. The results of this research show that the Q-mode cluster analysis classifies the sub-catchments according to the similarities in their variables while the R-mode cluster analysis classifies the variables into three effective groups. The first two factors of (FA) accounted for about 63 % while the first three factors accounted for about 93 % of the total variance in the data. This process helps in discovering the linear combinations that reflect the most variation in the data and also to discover and analyze the most important variables and rank them according to their direct effect on the output function which is the flood disaster.