Due to the significant role of rainfall on soil erosion in one hand and a limited number of rain gauge stations to record daily rainfall, on the other hand, using modeling techniques are inevitable. The main objective of this research is to map rainfall erosivity index for Meymeh watershed of Ilam Province, Iran. Input data were collected at 26 rain gauge stations for 23 years (1987-2010). After selecting representative stations in the study area, monthly and annual rainfall was statistically reconstructed for the period. Then, using Fournier equation, the index was calculated for all stations. Next, GIS-based geostatistical methods were used to produce the maps of the rainfall erosivity factor. An intensive variography analysis was used to indicate a spatial correlation between the observed and the estimated values of rainfall erosivity. Weighed interpolation methods have been used for erosivity index mapping, including linear and nonlinear interpolations such as IDW and GPI. Besides, RBF, LPI and Kriging method were tested. The results indicate that the LPI method with RMSE = 51.28 had the least error. It seems that LPI is an efficient model for rainfall erosivity factor mapping. The simplicity of the method makes it easily retrievable
کلید واژگان :Watershed; Geo-statistical Modeling; Rainfall Erosivity; GIS; Iran
ارزش ریالی : 300000 ریال
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