Flood modeling in watersheds using statistical analysis and morphometric characteristics (a case study of watersheds in Kurdistan province)

Morphometric analysis of a drainage basins and river network plays an vital role in understanding the hydrogeological behavior of the drainage basin . Therefore, the current research was conducted with the aim of modeling flood and its relationship with morphometric variables using multivariate regression. The research method is based on the destruction of morphometric parameters and statistical analysis, including correlation coefficient and linear regression analysis. In this regard, first, the studied basins have been selected using ARC GIS 10.5 software, and the limits of each one has been determined. Then, their morphometric characteristics have been extracted. The Flood discharge has also been reconstructed in return periods of 2 to 500 years using easy-fit software. For modeling, first, the linear relationship between each morphometric variable as an independent variable with flood discharge as a dependent variable was investigated. After ensuring the linear relationship between variables and flood discharge, correlation between each variable and flood discharge was calculated. The variables with the highest correlation were watershed area, basin length, and surface flow length. Using multivariate regression, modeling was used for independent variables and flood discharge. The results show that as the return period increases, the relationship between independent variables and flood discharge increases, So that the correlation of the area with the return period of 25 years is 0.609 and with the return period of 200 years is 0.677.also, the proposed models have more validity for flood prediction using multivariate regression analysis in return periods above 25 to 500 years.