Assessment of aquifer intrinsic vulnerability by the SINTACS method

Application of the SINTACS method for assessment of aquifer intrinsic vulnerability is demonstrated in the catchment areas of Jadro and Žrnovnica springs. Both Jadro and Žrnovnica are the springs of drinking water supplying the population of Split and surrounding settlements. A high-speed economic expansion in the catchment area accompanied with trend of increasing quantity of a number of contaminants in the spring water prompted comprehensive investigations with purpose of finalizing the Water Management Study of the Jadro and Žrnovnica springs. Results of the Study were treated by GIS tools and employed as input data for making the groundwater vulnerability map of the Jadro and Žrnovnica catchment areas. In addition to the standard method of defining the C factor which, in this case, is represented by the values of C(a), a modification is also introduced which takes into account the analysis of the sinkhole density.</p

Hydrogeological Characteristic of the Jadro and Žrnovnica Catchment

Upravljanje zalihama podzemnih voda velikih krških slivova zahtijeva opsežnu i detaljnu karakterizaciju cijeloga hidrogeološkog sustava. U ovom je članku prikazan dio rezultata dobiven tijekom istraživanja između 2005. i 2009. godine. Jedan dio rezultata odnosi se na relevantne geološke, strukturne i hidrogeološke kriterije za određivanje mjesta pogodnih za motrenje količine i kakvoće podzemnih voda u priljevnom području izvora Jadra i Žrnovnice pomoću dubokih opažačkih bušotina. Drugi rezultati razmatraju primjenu rezultata trasiranja i raspodjelu stabilnih izotopa kisika i vodika u izvorskim vodama Jadra i Žrnovnice kao i izvorskim vodama okolnih slivova rijeka Krke i Cetine pri odjeljivanju njihovih priljevnih područja. Dobivene spoznaje bit će vrlo korisne za daljnju zaštitu i upravljanje vrijednim zalihama podzemnih voda.A ground water resources management within the large karst catchemnt requires comprehensive and detailed characterization of whole hydrogeological system. In this article, a part of results obtained during the study period, between 2005 and 2009, is presented. One part of results applied to relevant geological, structural and hydrogeological criteria for determination of sites suitable for monitoring quantity and quality groundwater monitoring in the drainage area of the Jadro and Žrnovnica springs by the deep monitoring boreholes. The other results concerned application of the tracing test results oxygen and deuterium stable isotope distribution in the Jadro and Žrnovnica spring waters as well as spring waters of surrounding catchments of the Krka River and the Cetina River for delineation of their drainage areas. Obtained knowledge will be very useful for further protection and management of this valuable ground water resource

Recent hydrogeologic study of the Vis island

The Vis Island belongs to the group of the Middle Dalmatian islands. It comprises an area of about 90.2 km2. Morphologically, three belts of highlands and two depressions with karst poljes are significant. The highest point on the island is Hum with 587 m a.s.l. theisland’s water supply is organized from the water-supply station “Korita”, situated in the central part of island, in tectonically formed depression. There are two additional capturedobjects: the well K-1 above the Komiža town and the spring “Pizdica”. The most important hydrogeological role on the island have two hydrogeological barriers, one in the KomižaBay, completely made of impermeable igneous and clastic rocks, and another one, the recently recognized relative barrier in the area of Dra~evo, Plisko and Velo polje. Since the island karst aquifer is in permanent dynamic relation with seawater, classical geologic,structural and hydrogeologic investigations have been performed with application of hydrogeochemical methods taking into account the natural chemical tracer content of groundwater and its variations in different hydrologic and vegetation conditions. Precipitationregime is very unfavorable with regard to the recharging of island’s aquifer, because dry periods are usually very long. During the summer tourist season, when the number of inhabitants and fresh water consumption considerably increase, amounts of island’sgroundwater suitable for water supply and irrigation rapidly decrease. Sometimes, insufficient quantity of fresh water on the Vis Island causes restrictions. Concerning the development of tourist potential and the present agricultural activities, summer lack ofwater is a serious restrictive factor. Some results of the performed hydrogeological study, important as a basis for island’s fresh water potential assessment, will be presented