Analysis of human induced changes in a karst landscape - the filling of dolines in the Kras plateau, Slovenia.

A comprehensive analysis of the increased pressure on karst landscapes due to expansive economic and urban development is presented with the aim of evaluating changes in land use and their deleterious effects on karst relief forms. The study focuses on two areas surrounding the relatively quickly growing settlements of Hrpelje-Kozina and Divača on the Kras plateau (Slovenia) that have been subjected to intensive urban and business development and traffic since the motorway was brought to their vicinity fifteen years ago. National legislation loopholes and technological improvement were the cause of the commonly unsupervised human encroachment which caused the widespread degradation of the landscape. By comparing different topographical and ortophotographical materials from the past four decades and by detailed field inspection of land use and environmental changes, as well as the morphometrical characterization of dolines, the following results have been found: due to the population growth in the past four decades (39% and 50%, respectively), an increase of settlement area by 18 and 11 percentage points took place. Consequently, between 25 and 27% of dolines have disappeared or have been extensively modified (filled up and leveled). According to the local spatial plans, an additional 18% to 28% dolines are endangered. Broad human induced changes in the karst landscape have resulted in a noticeable increase in landscape deterioration, which is consistent with similar phenomena observed in other regions. Due to the extreme susceptibility of the karst to human activities that may lead to the degradation of its exceptional esthetic and environmental value, the alteration of karst processes such as corrosion, endangering of unique habitats and the quality of non-renewable natural resources, it is necessary to promptly define measures for its protection at the national level.