Investigation of Applicability of Soil Map Units to Estimate the Spatial Variability of Soil Erodibility

Abstract

Soil erodibility  is  one  of  the  six  components  affecting  water  erosion  of  the universal soil loss equation (USLE). K-factor is best obtained from direct measurements on natural plots. This is an infeasible task on large scales.  To overcome this  problem,  measured  K-factor values have been related to soil properties and the soil classification maps are used. The current research examines the ability of the soil maps for calculation of erodibility factor in the watershed scale. This subject was  followed  by the investigation  of  difference of erodibility components among thesoil types of Darabkola Watershed. Also, the geostatistical technique with Kriging method is used for the representation of the  spatial distribution of K-factor. Results  showed that among the  K-factor components,  percent  of  silt,  structure  class  and permeability had a significant difference between some of soil types, and other components  and K-factor didn’t have a significant difference. In conclusion, any coincidence seemed between erodibility map and soil type map.