A DETERMINATION OF AREA OF POTENTIAL EROSION BY GEOGRAPHIC INFORMATION SYSTEMS

Accelerated water erosion is the major problem of agricultural soils all over the world and also in the Slovak Republic. Accelerated erosion occurs in 55 % of agricultural land. It belongs to physical degradation of fertile land, and the whole process is irreversible. Therefore, it is very important to localize the presence of accelerated erosion and apply the basic principles of soil erosion control. Geographic information systems (GIS) are an effective tool for various environmental analyses, so it can also be succesfully used for determination of potential erosion intensity. The aim of this work was to create a map of domain areas that describes potential water erosion. As an area of interest the cadastral territory of Topolcianky in the Slovak Republic was selected. For this purpose the GIS software Arcview from ESRI was used. Water erosion process was modelled by universal soil loss equation (USLE) which computes an average annual soil loss. The limit values of acceptable intensity of soil loss are defined in the Collection of Laws of the Slovak Republic (Act No 220/2004 Coll). The final result of this work is a map that divides the domain area according to potential annual soil loss into several categories. In this case the domain area was divided into four categories. The first category, named slightly threatened soil, had 620,05 ha of agricultural land (77,48 per cent of the total agricultural land of domain area). The second category, called averagely threatened soil, had 106,56 (13,32 per cent of the total agricultural land). The third category (intensively threatened soil) had 70,91 ha (8,86 per cent of the total agricultural land) and finally the fourth category (very intensively threatened soil) had 2,74 ha (0,34 per cent of the total agricultural land).