The influence of topographical factor calculation on the estimation of water erosion intensity using geographical information systems

Abstract

During the recent years, there has been a surge of concern and attention in Europe to soil degradation processes that deteriorates soil quality by partially or entirely damaging one or more of its functions. Degradation processes occurring in Europe are widely studied and incorporated to soil protection policies on national and European levels. One of the most widespread forms of soil degradation in Europe is soil erosion by water which affecting an estimated 105 million ha, or 16% of Europe's total land area (excluding the Russian Federation). The soil erosion modeling may be useful in the design of the erosion-control measures and the evaluation of land-use management practices. Over time, different empirical models have being developed however, the Universal Soil Loss Equation (USLE) given by Wischmeier and Smith is extensively used for prioritization of the watersheds. Significant role in generation, quantification and management of the soil erosion model parameters have geographical information systems (GIS). The importance of the GIS techniques integration to quantify the surface erosion risk is determined by the speed of the performing operations, the accuracy of the results and the possibility of their spatial representation. The paper is focused on the determination and evaluation of water erosion intensity in the basin of river Tisovec in Slovakia. Water erosion is modeled using the universal soil loss equation through geographic information systems. There are used two methods for calculating the topographic factor (LS factor). The first variant of the LS factor calculation is methodology according to the USLE using the manual method with choice of characteristic drainage profiles. The second option is to determine the LS factor by Mitasova methodology. Modeling of water erosion intensity using geographic information systems can establish in which parts of the land limit values of soil loss are exceeded and thereby change crop rotation or design and implement the erosion control practices.