The relatively new sea level satellite altimetry and secular coastal tide gauge data made the reconstruction of sea levels on regional and global scales possible about one century back. Due to better ...estimations of the Earth’s crustal, glacial, tectonic, and other possible motion biases in tide gauge data, some additional improvements can be expected in sea level reconstructions, analysis, and predictions. A more detailed review of published sea level-related results was conducted for the Eastern Adriatic coast, including the operation of the tide gauge network and data processing, crustal movement estimations, and the establishment of a new reference height system in Croatia, based on five tide gauge sea level data. It was shown that sea level variation and trend-related indicators are spatially homogeneous, especially on a sub-Adriatic scale. The regional Adriatic Sea mean sea level rise rate of +2.6 mm/year for the satellite altimetry era (1993–2019) is less than the global mean sea level (GMSL) rise rate of +3.3 mm/year for the period of 1993–2022. Several empirical methods for GMSL projections and expected IPCC (Intergovernmental Panel on Climate Change) assessments until the end of the 21st century are considered.
The influence of the meteorological parameters (precipitation and air temperature) during blasting in clay has a direct impact on the success of blasting. In the case of large amounts of ...precipitation (rain and snow) recorded in the subject area, blasting in clays cannot be carried out due to the grain of the clay and the inability to access the subject area. Moreover, the air temperature in the subject area affects the blasting performance. The most ideal temperature for blasting in clays is between 15 and 25 °C because then the clay has the best geotechnical characteristics. The research was conducted on the exploitation field Cukavec II, which is located near the city of Varaždin in the Republic of Croatia. Amount of precipitation and air temperature were considered to obtain the best blasting effect. Influence of meteorological parameters on the amount of the explosive charge and stemming length when blasting in clays was demonstrated via models based on Artificial Neural Networks (ANN). The ANN model network consists of a Long Short-term Memory (LSTM) part to process time dependent meteorological data, and fully connected layers to process blasting input data. Two types of explosive charges were compared, Pakaex and Permonex V19.
With its quantities of groundwater, the Zagreb aquifer is an irreplaceable water-supply resource that forms the basis of the water-supply of Zagreb, the capital and largest city of the Republic of ...Croatia. The depth of the Zagreb aquifer system is about 100 m at the deepest part, and the two main aquifers of the aquifer system can be separated vertically by low-permeable clay deposits. In the area of the Zagreb aquifer, there are several active and reserve public water-supply sites, the largest of which are Mala Mlaka and Petruševec. The groundwater level of the Zagreb aquifer is directly related to the water levels of the Sava River, so any erosive change in the Sava riverbed decreases the groundwater levels in the aquifer. In the last 50 years, the groundwater levels in the Zagreb aquifer have decreased significantly, being most pronounced in the area of the Mala Mlaka water-supply site. This has affected the normal functioning of the public water-supply because the suction baskets of the pumps in the dug wells at the Mala Mlaka water-supply site occasionally remain partially or completely in the unsaturated aquifer zone during low groundwater levels, which reduces capacity or prevents pumping from these water-supply facilities. Immediately next to the Mala Mlaka water-supply site is the Sava-Odra Canal, which was built to protect Zagreb from flooding and into which the Sava River flows when its flow rate exceeds 2350 m3/s. This reduces the flow rate of the Sava River near Zagreb and the possibility of flooding urban areas. To prevent problems with groundwater levels at the Mala Mlaka water-supply facilities and to enable normal water-supply, even in extremely dry periods, several variants of managed aquifer recharge (MAR) are proposed here. In order to determine the optimal solution for MAR and to enable the normal functioning of one of the main sites of water-supply in the Zagreb water-supply system. Groundwater flow for the period of 2006 to 2010 was simulated for six different variants of MAR. One assumes a constant potential in the Sava-Odra Canal, three are related to recharge from the Sava-Odra Canal with different backwater levels in the infiltration facility (elevations of 114, 114.5, and 115 m a.s.l.), and two with three absorption wells upstream of the Mala Mlaka water pumping station (injection of 300 L/s each and 500 L/s each). The most favorable method to recharge artificially the Zagreb aquifer near the Mala Mlaka pumping station is achieved with an infiltration facility using an elevation of 115 m a.s.l. The use of such a facility will enable the smooth operation of the water pumping station and the possibility of increasing the pumping quantities at the Mala Mlaka water pumping station for the future development of the area.
Monitoring and detection of seawater intrusion in coastal aquifers in Croatia are one of the water management measures that attempt to notice an increase in salinity in time. Bokanjac-Poličnik is the ...coastal aquifer in Croatia that is at the risk of seawater intrusion. In that area, analysis of hydro-chemical indicators will be conducted due to the occasional seawater intrusion that occurs on wells that are included in the water supply system for the City of Zadar and surrounding villages. Due to the increased exploitation during the tourism season in summer and climate changes, salinization process is more intense. The presented results indicate that two of four wells on the case study area are under the influence of salt marine water.
Downstream of the Plitvice Lakes National Park, water that pass through the water system of the lakes begins its flow as the Korana River. A few hundred meters downstream of the source zone, during ...the summer dry periods, there are losses of water in the riverbed resulting in its total drying. The sinking zone in that area is built of high permeable carbonate rocks and with the appearance of less permeable dolomite rocks, about 17 km downstream, the Korana River becomes a permanent river. This paper focuses on the explanation of hydrogeological relations in the zone where losses of water occur in the riverbed, relationship to the neighbouring Una River catchment, as well as possibilities of relocating the source of water supply from the Kozjak Lake (Plitvice Lakes) to the new site in the sinking zone of the Korana River. For this purpose hydrogeological researches were performed, with drilling of several piezometric boreholes and two tracing tests to determine the direction of groundwater flow during the dry season. The results show that during the dry periods in the sinking zone of the Korana River the groundwater level with active aquifer is about 25 m below the riverbed. This opens up the possibility of additional research to solve the problem of water-supply and relocation of water-supply capture in this area. Two tracing tests showed a connection with the Klokot spring (Bosnia and Herzegovina) in the neighbouring Una River catchment, which points to the transboundary character of this aquifer. At the source of the Klokot minimum discharge is around 3 m3/s and the maximum more than 75 m3/s. The capturing of about 60 l/s for water-supply in the Korana River sinking zone will not have impact on the amount of discharge at the Klokot spring. Key words: Dinaric karst, Korana River sinking zone, Plitvice Lakes, tracing test, transboundary aquifer, groundwater capturing. Hidrogeologija ponornega območja reke Korane dolvodno od Plitviških jezer, Hrvaška Dolvodno od Nacionalnega parka Plitviška jezera vode, ki tečejo skozi sistem jezer, oblikujejo reko Korano. Nekaj sto metrov pod to izvirno cono v času poletnih sušnih obdobij voda v strugi ponika in s časom povsem presahne. Ponorno cono gradijo zelo dobro prepustne karbonatne kamnine in šele po prehodu na manj prepustne dolomite približno 17 km nižje po strugi Korana postane stalna reka. V članku so obravnavane hidrogeološke razmere v coni ponikanja vode v strugi in odnosi s sosednjim porečjem reke Une, pa tudi možnosti prestavitve vira oskrbe s pitno vodo iz jezera Kozjak (Plitviška jezera) na novo lokacijo v ponorni coni reke Korane. V ta namen so bile izvedene hidrogeološke raziskave, izvrtanih je bilo več piezometrskih vrtin in izvedena sta bila dva sledilna poskusa za določitev smeri podzemnega toka v času nizkih vod. Rezultati so pokazali, da je v sušnih obdobjih v ponorni coni reke Korane nivo podzemne vode z aktivnim vodonosnikom približno 25 m pod strugo. To odpira možnost dodatnih raziskav za rešitev problema oskrbe z vodo in prestavitve zajetja vode na tem območju. Oba sledilna poskusa sta dokazala povezavo z izvirom Klokot (Bosna in Hercegovina) v sosednjem porečju reke Une, kar kaže na čezmejni značaj vodonosnika. Minimalni pretok izvira Klokot je približno 3 m3/s, maksimalni pa več kot 75 m3/s. Zajetje za oskrbo z vodo v ponorni coni reke Korane z izdatnostjo približno 60 l/s ne bo imelo vpliva na pretok izvira Klokot. Ključne besede: Dinarski kras, ponorna cona reke Korane, Plitviška jezera, sledilni poskus, čezmejni vodonosnik, zajetje podzemne vode.
The Plitvice Lakes National Park, founded in 1949, is located in the central part of the Dinaric karst region in Croatia. Large karst springs and 16 lakes separated by tufa barriers and waterfalls ...are the fundamental natural phenomenon of the national park, which has a million visitors a year. Lakes are recharged by water from the mountainous region of Lika, and the runoff is directed towards the Black Sea catchment. The whole area of the National park is composed of carbonate rocks with different levels of natural permeability and very complex tectonic relationships, which allowed discharge of groundwater, maintaining the lake and finally partial loss of water to the karst underground after passing through the lake system. Proscansko and Kozjak are the two largest lakes which dominate and by their internal dynamics ensure maintenance of the high water quality of the whole system. A conceptual hydrogeological model of the Plitvice Lakes was the result of complex research in the framework of international cooperation between the University of Zagreb and the Joanneum Research Institute in Graz. The research identified completely new data about the genesis of the water system, the hydrogeological characteristics of the karst water catchment, the dynamics of the water in the lakes, locations of water loss from the Plitvice Lakes system, the hanging position of Lake Kozjak in relation to groundwater and a whole range of other data important for the preservation and protection of water resources in the National Park. Throughout the project were made 3022 measurements of different physicochemical parameters, 7885 of the chemical analysis of water and 1082 analysis of stable isotopes.
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 Žrnovnica, 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.
Karst aquifers in the Dinaric karst are very rich with groundwater and are a very important resource for public water supply. The characteristics of the Dinaric karst are the lack, or very thin ...layer, of covering deposits, large amounts of precipitations, high groundwater velocities, very deep groundwater flow with a lot of faults and fault zones, pits to groundwater, concentrated sinking and large karst springs, making them extremely vulnerable to all anthropogenic influences, which are very quickly transmitted to the aquifer. Numerous multiparameter methods have been developed in the last 20 years to determine the level of vulnerability of aquifers. Each of them has its own specifics and is well adapted to the climate and region for which it was developed. The Karst Aquifer Vulnerability Assessment (KAVA) method was developed in accordance with all the characteristics of the deep karst aquifers of the Dinaric karst and tested on several basins in the area. It was developed as a part of the Global Environment Facility United Nations Environmental Programme – the Mediterranean Action Plan Strategic Partnership for the Mediterranean Sea Large Marine Ecosystem (GEF UNEP/MAP MedPartnership Project). This paper presents the KAVA method and its application to two characteristic karst basins of the Dinaric karst: the Novljanska Žrnovnica spring catchment area and the Bakar Bay catchment area.
The study addresses homogeneity testing of annual discharge time series for eight hydrological stations and five annual climate time series for one weather station in the Kupa River Basin, between ...Slovenia and Croatia, and global annual average surface temperature time series for the period 1961-2010. The standard normal homogeneity test (SNHT) was used to detect both abrupt and gradual linear trend homogeneity breaks. The results reveal natural change points at the beginning of the 1980s. Absolute homogeneity testing of average annual weather station-level air pressure, annual precipitation, differences between precipitation totals and potential evapotranspiration and surface runoff from the independent observation time series confirmed an abrupt shift, also at the beginning of the 1980s. The trend of local air temperature for 1985-2000, which partly coincides with global surface temperature trend for 1974-2005, strengthened the river discharge regime shift since the beginning of the 1980s. These results could improve climate variation monitoring and estimation of the impact of climate variation on the environment in the area. Generally, an indication of climate regime change points and an assessment of their duration could provide significant benefits for the society.
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