Assessment of Soil Erosion Risk using a Fuzzy Model in Gharnaveh Watershed, Golestan

Erfanian, Mahdi; Ghaharahmani Saatloo, Parisa; Saadat, Hossein

Assessment of Soil Erosion Risk using a Fuzzy Model in Gharnaveh Watershed, Golestan

Document Type : Complete scientific research article

Authors

¹ Assisstant Professor, Urmia University, Urmia, Iran

² Graduated M.Sc. Student in Watershed Management Engineering, Faculty of Natural Resources, Urmia University

³ Assistant Professor, Soil Conservation and Watershed Management Research Institute, Tehran

Abstract

The awareness of soil erosion risk in watersheds can facilitate the identification of critical areas as well as the prioritizing of soil conservation and management plans. The present research aims to develop a new fuzzy model and its validation for soil erosion risk mapping in Gharnaveh watershed, located in the Golestan province, Iran. Soil erosion risk mapping was conducted in three steps: at first, the map of soil protection index (SPI) (NDVI) was created using two primary factors of Land Use-Land Cover (LU-LC) and the normalized difference vegetation index. At the second stage, a map of potential erosion index (PERI) was created based on three raster layers of slope, rainfall erosivity and soil erodibility. Finally, The output of the fuzzy modeling (the SPI and PERI maps) were combined to produce the actual erosion risk index (AERI) map. The RUSLE model was utilized to validate the fuzzy model of soil risk map. The kappa coefficient of the class of very high risk (VH) reveals that the reclassified AERI map could identify relatively well the critical areas with high soil erosion potential in the Gharnaveh watershed compared with the RUSLE soil erosion risk map (as reference map). The findings in this research are very useful for managers, decision makers with respect to projects implementation, the prioritization of sub-watersheds and choosing proper watershed management practices.

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