Isotope compositions of carbon and oxygen in calcite de­posited to stalagmites are regarded as important proxies for paleo-climate. The number of papers reporting such proxies rises rapidly. Additionally cave monitoring is be­ing performed to observe chemical properties of the wa­ter dripping to speleothems, the partial pressure of CO2 in the soil above the cave and in the cave atmosphere, and other parameters outside the cave to relate recent climate conditions to recently deposited calcite.

There are, however, physical and chemical processes independent of climatic conditions, which also contrib­ute to the isotope composition and which can add noise to the climate signal. In this letter I resume these from the current literature to open a more easy access to this problem than available from the current original publi­cations.

Heaven’s Cave is located in the centre of the Phong Nha-Ke Bang national park, about 500  km southern from the Vietnamese capital and 40 km from the city of Dong Hoi. Phong Nha-Ke Bang national park is protected also as a UNESCO world heritage site. Due to weak economic situation in this region as a result of lack of natural resources, karst tourism represents an important opportunity for raising the quality of live in the province. A proposal to adapt non-touristic Heaven’s Cave for tourism was presented to Karst Research Institute ZRC SAZU in 2006. Because the caves are sensitive ecosystems and all activities in them should be carefully implemented, our task was to make basic survey and map the cave, to perform a speleological and touristic research, to propose possible interventions for adapting the cave for tourism and to prepare a strategy for tourism development in this area. The latter should also show us if some interest is present among tourists for new show cave in this region. From this point of view this study does not represent systematic long-term approach for adapting a cave for tourism but rather a short study of a cave with potential to be show cave in remote area of Central Vietnam. Approach used in this study should be used in similar environments as a first step to estimate if weakly known cave is environmentally and economically suitable for development for touristic purposes.

This paper presents an approach for solving the problem of exploitation of freshwater in the coastal karst aquifer during summer dry periods in the conditions of potential salt water intrusion. The approach is presented on the example of spring zone Novljanska Zrnovnica, situated in the northern part of Croatian Adriatic coastal region. The spring zone is used for water supply (about 250 l/s) of an important tourist area of Crikvenica and Novi Vinodolski. After unsuccessful attempts of physical separation of freshwater system from the sea influence, by construction of grout curtain, hydrogeological studies have focused on the possibility of groundwater capturing in the hinterland of discharge zone, outside of the zone of periodical salinity. The final research results with the exploitation well in the spring hinterland can serve as a model for research and exploitation of drinking water in natural conditions of unstable freshwater-saltwater interface in similar natural conditions.

This paper presents an approach for solving the problem of exploitation of freshwater in the coastal karst aquifer during summer dry periods in the conditions of potential salt water intrusion. The approach is presented on the example of spring zone Novljanska �rnovnica, situated in the northern part of Croatian Adriatic coastal region. The spring zone is used for water supply (about 250 l/s) of an important tourist area of Crikvenica and Novi Vinodolski. After unsuccessful attempts of physical separation of freshwater system from the sea influence, by construction of grout curtain, hydrogeological studies have focused on the possibility of groundwater capturing in the hinterland of discharge zone, outside of the zone of periodical salinity. The final research results with the exploitation well in the spring hinterland can serve as a model for research and exploitation of drinking water in natural conditions of unstable freshwater-saltwater interface in similar natural conditions.

23rd International Karstological School "Classical Karst", Postojna, June 15th to 21st 2015

Caves - exploration and studies combined with the 50th anniversary of the International Union of Speleology - UIS : program & excursions & UIS & abstracts