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

Document Type: Research and Full Length Article

Authors

1 Watershed Management Engineering and Science, Lorestan University

2 Department of Forest Science, University of Ilam

3 University of Agriculture and Natural Resoureces, Sari

4 Faculty Member, University of Agriculture and Natural Resources, Sari

Abstract

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

Keywords