Rainfall erosivity research on the territory of the Czech Republic

Water erosion is a main factor of degradation of soils used for agriculture in the Czech Republic. For landscape conservation purposes the soil erosion risk is defined here mostly by USLE method published by WISCHMEIER and SMITH (1978). Within USLE the precipitation impact on erosion is a function of rainfall kinetic energy and intensity represented by R-factor. In the Czech Republic historically and recently several research teams have analyzed rainfall data to assess rainfall erosivity. The article is based on review of different approaches and results of recent rainfall erosivity studies. Those studies differ in both the data used for erosivity definition and the methodology applied. At the end the article presents results of the most recent study on rainfall erosivity spatial distribution over the Czech Republic performed by Research Institute for Amelioration and Soil Conservation (VUMOP), Czech Hydrometeorological Institute (CHMI) and Czech Technical University in Prague (CTU). The analysis was based on digital rain gauge data from automatic stations of the CHMI. The erosive rains were derived from continuous 1 minute step 10-year rainfall data (2003-2012) from 245 stations, all necessary quality checks and corrections were adopted. Based on the research recent annual R-factor values in the stations vary from 37 to 239 N.h(-1) (values over 100 are located in mountain regions with minimum agricultural land). The raster based R-factor map used for erosivity definition in cross compliance soil erosion risk maps of Ministry of Agriculture adopted values varying from 37 to 110 N.h(-1) over the Czech territory.