Geomorphological and hydrological characteristics of small sinking streams- examples from Kordun karst

Kordunski krš predstavlja dodirno područje dviju megageomorfoloških regija: Panonske ne-krške i Dinarske krške. Otjecanjem vode dolazi do oblikovanja reljefa i pojave kontaktnog krša. Cilj rada bio je geološko-geomorfološkim i hidrološkim analizama istražiti uvjete nastanka i razvoja manjih ponornica i njihovih drenažnih bazena na četiri primjera. Geološkogeomorfološkim analizama istraživan je utjecaj geološke građe podloge na reljef koji je ponornica svojim tokom oblikovala. Proučavani su stijenski odnosi nepropusnih i propusnih naslaga, njihova visinska raspodjela, prostorni raspored te rasjedi i pukotinski sustavi. Na tako malom području istraživanja utvrđena su tri morfogenetska tipa reljefa : fluviodenudacijski, fluviokrški i krški. Hidrokemijska svojstva vode ovise o geološkoj građi podloge stoga su na primjeru Dunjak izmjereni fizikalno-kemijski parametri vode koji su odgovarali vrijednostima očekivanim za karbonatnu podlogu. Izmjeren je protok vode prije i nakon ulaska u krški vodonosnik koji je ukazivao na hidrološki period s malo padalina što je imalo utjecaj na koncentracije mjerenih fizikalno-kemijskih parametara vode.Kordun karst represents the meeting belt of two megageomorphological regions: Panonian non-karst and Dinaric karst. Water runoff has an impact on relief formation, resulting in contact karst formation. Research aim of this thesis was to establish conditions of formation and development of small sinking streams and their watersheds on four examples. Geologicalgeomorphological analysis were used to explore impact of bedrock geology on relief. The relationship between permeable and impermeable rocks, hypsometry, spatial distribution, faults and fracture systems were analyzed. In such a small area of research, 3 types of genetic relief were established: fluvioerosional, fluviokarstic and karstic. Hydrochemical water characteristics depend on bedrock geology, therefore, measured physico-chemical properties of Dunjak sinking stream were corresponding to values expected for carbonate bedrock. The water flow was measured before and after entering the karst aquifer, which indicated a hydrological period with little precipitation that had an impact on the concentrations of the measured physico-chemical parameters of the water