Estimation of Stormwise Sediment Yield of Gully Erosion Using Important Rainfall Components in Different Land Uses of Zagros Forest, Iran

Abstract

Erosion is one of the important social-economic problems in Iranian<br />catchments that have been posed by surface water vastness and runoff production. So, the<br />study of water resources, soil erosion and effective factors is of high importance. Gully<br />erosion also extends in many parts of Iran and its study particularly in viewpoint of<br />sediment yield is therefore very important and should be taken into account. In order to<br />investigate the relationships between sediment yield of gully erosion and rainfall<br />parameters such as amount, intensity and duration of them, the present study was<br />conducted in Alashtar, Lorestan province, Iran. For this purpose, 18 digitalized linear and<br />frontal gullies have been identified and morphological characteristics of the gullies were<br />specified at the beginning and after five Storm Runoff productions in November 2007 to<br />May 2008. Then, using matrix correlation and regression analysis, the most effective factor<br />in the sedimentation of Gully erosion was determined. The results have showed that the<br />most important climatic factors that can be pointed out with respect to the sedimentation of<br />gullies were the maximum and average rainfall intensities. Results of regression analysis<br />have also indicated that the maximum intensity of rainfall is the most important factor in<br />the study area and has the ability to estimate sediment and erosion rates caused by the<br />storms with the coefficient of determination as (R2=0.91) and the standard error value of<br />18.8.