Spatial and temporal patterns of soil
According to Mitasova et al. (2013), the amount of erosion and sediment transport varies between two limiting cases: the detachment capacity limited case and the sediment transport capacity limited case. When the transport capacity of overland flow exceeds its detachment capacity, the amount of erosion and sediment transport is detachment capacity limited, i.e. no deposition occurs. Assuming that the critical shear stress is negligible (Mitasova et al., 2013), erosion will be equal to the detachment capacity, which is the starting point leading to L189 that is the basis for the well-known erosion model USLE and its revised version RUSLE. The RUSLE3D is a revision and update of the widely used USLE and RUSLE, and it is suitable for complex terrain and GIS-based soil erosion modelling. It has a number of improvements for its application at the watershed scale, in contrast to the USLE designed for agricultural fields (Garcia Rodriguez and Gimenez Suarez, 2012). The RUSLE3D uses the same factorial approach employed by the USLE and RUSLE, but different equations to obtain the same parameters:equation(2)A=R⋅K⋅LS⋅C⋅PA=R⋅K⋅LS⋅C⋅PwhereAis the computed annual soil loss per unit area (Mg ha− 1 year− 1);Ris the rainfall–runoff erosivity factor (MJ mm ha− 1 h− 1 year− 1);Kis the soil erodibility factor (Mg h MJ− 1 mm− 1);LSis the topographic factor (dimensionless);Cis the cover and management factor (dimensionless); andPis the support practice factor (dimensionless).