Prostorni raspored i gustoća ponikava jugoistočnog Velebita

Abstract

Dolines are considered to be among the most prominent karst formations, which is why they can serve as diagnostic forms of karst. Their spatial distribution and density are important indicators of an area’s degree of karstification, as well as of an overall geomorphological development. The aim of this paper is to determine the spatial distribution and the density of dolines, and also to analyse the influence of geological structure and morphometric features of the terrain (hypsometry, slope inclination, relative relief) on the spatial distribution of dolines in the area of southeastern Velebit. Moreover, for the first time with regards to the Croatian karst, the spatial distribution of dolines was compared with the spatial distribution of entrances into caves in the southeastern Velebit’s area of Crnopac. The data on the dolines’ position were adopted from 1:25,000 scaled topographic maps. All data were digitalised and analysed with ArcGIS 10.1 software in the GIS laboratory of the Geographic Department of the Faculty of Science in Zagreb. The research showed a strong influence of morphometric parameters of the relief on dolines’ density. The most prominent occurrence of dolines is linked with the areas ranging from 1000 to 1200 meters of altitude, slope inclination lower than 2° and the relative relief of 100 – 200 m per km2. Furthermore, the highest density of dolines was recorded in the Jurassic carbonate layers, while it was determined that the zones of main faults do not have a significant influence on the increase of dolines’ density. A high degree of correlation was determined by comparing spatial distributions and density of dolines and entrances into caves.

GIS-based analysis of doline density on Miljevci karst plateau (Croatia)

“…This analysis thus indicates only a minor and localized influence of the fault on doline formation in the research area. Similar results were obtained from analogous research in SE Velebit (Marković et al, 2016) and on Slunj Plateau (Bočić et al, 2010). However, in this research only the most significant faults were considered.…”

“…In the east, the highest con- is low. Still, density of 30-34.23 dolines/km 2 could be considered as significant as it is in concordance with average doline density on Slunj karst plateau (42 dolines/ km 2 , Bočić et al, 2010) and higher than average density in mountainous regions: 27.5 dolines/km 2 in NW area of Velika Kapela (Pahernik, 2000), 19 dolines/km 2 in Northern Velebit and Senj ridge (Faivre, 1992(Faivre, , 1995, 18.4 dolines/km 2 in Biokovo (Bočić & Pahernik, 2011) and 10.6 dolines/km 2 in southeastern Velebit (Marković et al, 2016). Spatial distribution of dolines is important indicator of the karstification degree (Ford & Williams, 2007).…”

“…They mainly form doline fields and long rows along contacts, on fractures, joints and smaller faults (Bognar et al, 2012). Characteristics and spatial distribution analysis of doline density revealed that lithology, tectonic structure and relief morphometric characteristics have large impact on doline formation and distribution (Faivre, 1992(Faivre, , 1995Mihljević, 1994;Pahernik, 2000;Faivre & Bocquet, 1999;Faivre & Reiffsteck, 1999, 2002Faivre & Pahernik, 2007;Telbisz et al, 2009;Bočić et al, 2010;Buzjak, 2011;Pahernik, 2012;Marković et al, 2016). Some of these works contributed also to a modern digital modelling of relief and to use of GIS in digital analyses and visualization of spatial data in geomorphic research.…”

Karst Geoheritage of Tara National Park (Serbia) and Its Geotouristic Potential

“…The median planform area for the entire study territory is 711 m 2 . This provides an opportunity to compare Tara NP with other karst regions (e.g., Aggtelek Karst/Hungary, Telbisz (2001); Miroč/Serbia, Telbisz et al (2007); Velebit/Croatia, Marković et al (2016); Munții Pădurea Craiului/Romania, Telbisz et al (2015); Taurus/ Turkey, Öztürk et al (2018)). Based on this, it turns out that in the case of the Tara plateau the density is medium, and in the case of the other sub-areas the density is particularly low.…”

Karstic Microrefugia Host Functionally Specific Ant Assemblages

“…Botanists have long recognised the valuable role of these habitats as ideal natural laboratories in which to study multiple environmental gradients, thermal stability and their effects on plant species composition and vegetation patterns. Studies have shown that dolines may provide microhabitats for unique plants that are rare or absent from the surrounding landscape (Beck von Mannagetta, 1906;Horvat, 1953;Kobal et al, 2015), further reinforcing the idea that these depressions can function as habitat islands (Özkan et al, 2010;Bátori et al, 2014Bátori et al, , 2017Su et al, 2017). In addition, the accumulation of cold-adapted plants (e.g., high montane and glacial relict species) within certain microhabitats of dolines -such as poleward-facing slopes and bottoms -is a prime indicator of the presence of current warm-stage microrefugia.…”