بررسي ارتباط بين پارامترهاي بارندگي و عامل فرسايندگي باران در استان خوزستان

An Investigation of Relationship between Precipitation Parameters and Erosivity in Khuzestan, Iran

The goal of this study is the investigation of relationship between rainfall parameters and USLE R factor. In this method, at first, rainfall kinetic energy must be calculated and then its erosivity computed by using maximum 30 minutes rainfall intensity. 3 meteorological stations in Khuzestan province and one station in Kohgiloyeh & BoyerAhmad and Boushehr provinces were selected and their recorded hyetographs of J3 years were analyzed. For all hyetographs, rainfall erosivity was computed monthly, seasonally and yearly and also corresponding rainfall parameters were extracted. Temporal and spatial variations of rainfall erosivity were studied and relationships between R factor and rainfall characteristics were investigated using regression analysis. Results showed that February, December, March and January and winter have the most erosivity risk. Spatial analysis of rainfall erosivity in the study area showed that Dezful has the maximum erosivity factor. Mean annual erosivity factor of Khuzestan province was computed 36.80 ton.m/ha.h. Regression analysis results showed strong relationship between rainfall amount (mm) and maximum 30 minutes rainfall intensity (cmlh) with R factor.