Author's personal copy Technical Note Analysis of human induced changes in a karst landscape — the filling of dolines in the Kras plateau, Slovenia Gregor Kovačič a , Nataša Ravbar b, ⁎ a University of Primorska, Faculty of Humanities, Science and Research Centre, Titov Trg 5, SI 6000 Koper, Slovenia b Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Karst Research Institute, Titov Trg 2, SI 6230 Postojna, Slovenia HIGHLIGHTS ► In the study areas, one quarter of dolines have disappeared in the past 40 years and more are endangered. ► Dolines are filled up with construction material resulting in landscape deterioration. ► Excessive human encroachment may have a great effect on karst hydrology or ecology. ► The current standards for karst protection are loose. abstract article info Article history: Received 1 October 2012 Received in revised form 20 December 2012 Accepted 1 January 2013 Available online xxxx Keywords: Environmental change Human activities Karst surface Geomorphology Karst protection Doline 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 topo- graphical 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 pro- cesses 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. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Karst landscapes most commonly formed in carbonate rocks (e.g. limestone, dolomite) that are water-soluble. Due to chemical weathering, distinctive surface and underground geomorphological features develop with particular hydrological functions (Bonacci, 1999; White, 2002; Ford and Williams, 2007). The most significant landforms for exposed karst landscapes are karrenfields, dolines (sinkholes), and swallow holes. These features on the land surface usually, but not necessarily, develop along fissured and fractured zones. The karst surface is very permeable and enables the immedi- ate infiltration of water into the underground system, where the karstification (solutional enlarging of fissures) creates cavities and organizes a flow net in a hierarchical manner. The interior of the karst is thus characterized by a three dimensional network of under- ground conduits and voids (Gunn, 1981; Bakalowicz et al., 1994; Drew, 1999; Gabrovšek, 2000; Klimchouk and Ford, 2000; Király, 2002; Worthington, 2009). Due to the described peculiarities of karst processes, these land- scapes are among the most vulnerable environments and the destruc- tion of dolines is among the topical issues in karst environments worldwide (Parise and Pascali, 2003; De Waele, 2009; North et al., Science of the Total Environment 447 (2013) 143–151 ⁎ Corresponding author. Tel.: +386 57001900. E-mail addresses: gregor.kovacic@fhs.upr.si (G. Kovačič), natasa.ravbar@zrc-sazu.si (N. Ravbar). 0048-9697/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.scitotenv.2013.01.002 Contents lists available at SciVerse ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv