Assessment of Spatial Distribution of Soil Erodibility in Khoor and Biabanak Region

At the present, erosion is one of the most important of environmental problems in the Iran watersheds. Therefore, determine the sediment and soil erodibility is very important for conservation and management of natural resources. The aim of this study is evaluate the spatial distribution of soil erodibility and relationship with some of the soil properties using geostatistical methods in the Khoor and Biabanak region. For this purpose, 33 soil samples were taken from depths of 0-50 cm along three transects from playa until mountain units to determining the components of sand, clay, silt, organic carbon and organic matter. Values of K factor and SEI were calculated by values of these parameters. Finally, to determine the spatial distribution, interpolation methods were tested and the most suitable method was chosen. The results showed that Radial Basis Function was the most suitable of interpolation method for the spatial distribution of the elements of sand, clay and K factor with RMSE 3.27, 3.22 and 0.0036, respectively. The simple Kriging method was suitable for carbon components and organic material with RMSE 0.34 and 0.59, respectively. For silt, Kriging Ordinary with RMSE 0.88, and for SEI index, Universal Kriging method with RMSE 0.0014 were suitable. According to the results of soil erodibility values, minimum and maximum amount of K factor with 0.025 and 0.07 t h MJ− 1 mm− 1, as well as minimum and maximum values of SEI with 0.03 and 0.07 are extensive in the East, and West and North West area, respectively.