EVALUATION OF CRITICAL POINTS AND THEIR CONTRIBUTING AREAS ACCORDING TO CURRENT LAND USE AS MAIN INPUT FOR DESIGN AND EVALUATION OF THE EFFECTIVENESS OF NATURE-FRIENDLY MEASURES

Abstract

Hydrological extremes (drought-flood) are a phenomenon that is occurring more and more frequently because of climate change. The human-altered landscape cannot sufficiently withstand these extreme phenomena. For this reason, society feels pressure on the design, and assessment, but especially the implementation of adaptation and mitigation measures in the landscape. For best-designed measures, it is crucial to determine where the given problem arises and what are the possibilities of its solution with subsequent quantification of effectiveness. In the Czech Republic, this problem is solved in the long term by processing flood maps and determining flood areas. In 2009, a methodology was created for the identification of places that are potentially threatened by flash floods [1]. In the interest area of the Dyje basin, 1356 critical points were determined by this methodology. The work's main goal was to evaluate these points and their contributing areas based on current data, and the summary and evaluation of the accessible data that will be used for proposals for measures. All analyses were made by using geographic information systems. It was specifically about evaluating the percentage representation of arable land, as one of the main criteria for determining the critical point. It was found that in almost 42 % of the critical points (or in their contributing areas) there was a decrease in arable land by more than 10 %. Furthermore, the occurrence of recorded erosion events was addressed. According to information from the Research Institute for Soil and Water Conservation, there were 622 erosion events in the Dyje basin area, and 43 % were in catchment areas of critical points. One of the crucial topics that are currently resonating in society in terms of proposals for measures in the landscape is drainage areas. According to vectorized documents from the Agricultural Water Management Company, these areas are in 57 % of the collection areas of critical points. The evaluation will further enter a multi-criteria analysis for the selection of a priority area, as the Dyje basin is quite extensive for more detailed analyses. Subsequently, protective measures close to nature will be designed and evaluated in the priority area using mathematical modelling.