Water erosion is considered as one of the major factors causing physical soil degradation in Slovakia. The moderate up to the extreme potential erosion risk was assessed about 65% of Slovak agricultural soil fund. Most studies concentrated on the application of empirical formulae, such as the Universal Soil Loss Equation (USLE), which is not always the appropriate tool for erosion studies. It was designed as a method to predict average annual soil loss caused by sheet and rill erosion, the USLE is often criticized for its lack of applications. While it can estimate long-term annual soil loss, it can not be applied to a specific year or a specific storm. To incorporate the impact of flow convergence, the hill slope length factor was replaced by upslope contributing area [Moore and Burch 1986, Mitašová et al. 1995, 1996, Desmet and Govers 1996]. The modified equation for computation of the LS factor is finite difference form in a grid cell representing a hillslope segment was derived by Desmet and Govers [1996]. Geographic information system is modern tool that enable the various equation for water erosion calculation to have a spatial variability. The final model locates potential erosion areas which need control and preventive measures according degree of erosion focused on rill the hill erosion.

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