Spatial distribution and geomorphological features of dolines, south-east Velebit

Cilj ovoga rada je analiza prostornog rasporeda i gustoće ponikava JI Velebita uz pomoć GIS alata. Analiziran je i utjecaj geološke građe i morfometrijskih karakteristika reljefa (nagib padina, hipsometrija, vertikalna rašlanjenost) na prostorni raspored ponikava. Na površini od 349,2 km2 zabilježene su 3684 ponikve. Glavni smjer rasprostiranja ponikava, SZ-JI, konforman je s pružanjem morfostruktura. Provedena analiza razlika u intenzitetu gustoće ponikava pokazala je snažan utjecaj tektonskih i litoloških čimbenika, ali i morfometrijskih parametara reljefa. Tektonika je primarno utjecala na prostorni raspored ponikava, a najveća gustoća ponikava zabilježena je u karbonatnim naslagama jure. S obzirom na morfometrijske pokazatelje ustanovljeno je da su najpovoljniji uvjeti za razvoj ponikava na nadmorskim visinama 1000 – 1200 m, nagiba padina manjeg od 2° i vertikalne raščlanjenosti reljefa 100 – 200 m/km2. Područje masiva Crnopca najokršeniji je dio JI Velebita koji se istične brojnim egzokrškim i endokrškim reljefnim oblicima.The aim of this study is to analyze spatial distribution and density of dolines in the SE Velebit, by using a GIS tools. The impact of geological structure and relief morphometric characteristics (slope inclination, hypsometry, vertical relief dissection) on the spatial distribution of dolines was also analyzed. In a 349,2 km2 area, 3684 dolines were recorded. The main orientation of doline field, NW-SE, is conforms to the orientation of the morfostructures. The analysis of spatial differences in doline density has revealed a strong impact of tectonics and lithology, but also of relief morphometric parameters. Spatial distribution of dolines is primarily influenced by tectonics, while the highest density of dolines was recorded in the Jurassic carbonate deposits. Considering the morphometric parameters it was found that the most favorable conditions for development of dolines are at an altitude 1000 – 1200 m, on slope inclinations lower than 2° and in a class of vertical relief dissection 100 - 200 m/km2. The area of Crnopac massif is the most karstified part of SE Velebit, which is characterized by numerous exokarstic and endokarstic relief forms