Explore the vast range of titles available.

Despite many existing approaches, modeling karst water resources remains challenging as conventional approaches usually heavily rely on distinct system knowledge. Artificial neural networks (ANNs), however, require only little prior knowledge to automatically establish an input–output relationship. For ANN modeling in karst, the temporal and spatial data availability is often an important constraint, as usually no or few climate stations are located within or near karst spring catchments. Hence, spatial coverage is often not satisfactory and can result in substantial uncertainties about the true conditions in the catchment, leading to lower model performance. To overcome these problems, we apply convolutional neural networks (CNNs) to simulate karst spring discharge and to directly learn from spatially distributed climate input data (combined 2D–1D CNNs). We investigate three karst spring catchments in the Alpine and Mediterranean region with different meteorological–hydrological characteristics and hydrodynamic system properties. We compare the proposed approach both to existing modeling studies in these regions and to our own 1D CNN models that are conventionally trained with climate station input data. Our results show that all the models are excellently suited to modeling karst spring discharge (NSE: 0.73–0.87, KGE: 0.63–0.86) and can compete with the simulation results of existing approaches in the respective areas. The 2D models show a better fit than the 1D models in two of three cases and automatically learn to focus on the relevant areas of the input domain. By performing a spatial input sensitivity analysis, we can further show their usefulness in localizing the position of karst catchments.

Hydrological models are widely used to characterize, understand and manage hydrosystems. Lumped parameter models are of particular interest in karst environments given the complexity and heterogeneity of these systems. There is a multitude of lumped parameter modelling approaches, which can make it difficult for a manager or researcher to choose. We therefore conducted a comparison of two lumped parameter modelling approaches: artificial neural networks (ANNs) and reservoir models. We investigate five karst systems in the Mediterranean and Alpine regions with different characteristics in terms of climatic conditions, hydrogeological properties and data availability. We compare the results of ANN and reservoir modelling approaches using several performance criteria over different hydrological periods. The results show that both ANNs and reservoir models can accurately simulate karst spring discharge but also that they have different advantages and drawbacks: (i) ANN models are very flexible regarding the format and amount of input data, (ii) reservoir models can provide good results even with a few years of relevant discharge in the calibration period and (iii) ANN models seem robust for reproducing high-flow conditions, while reservoir models are superior in reproducing low-flow conditions. However, both modelling approaches struggle to reproduce extreme events (droughts, floods), which is a known problem in hydrological modelling. For research purposes, ANN models have been shown to be useful for identifying recharge areas and delineating catchments, based on insights into the input data. Reservoir models are adapted to understand the hydrological functioning of a system by studying model structure and parameters.

Karst groundwater-dependent ecosystems (KGDEs) in the Mediterranean region are important in terms of ecosystem services and biodiversity but are increasingly under anthropogenic pressures and climate-change constraints. For this study, the ecohydrological characteristics, threats, and protection status of 112 selected KGDEs around the Mediterranean Sea, including caves, springs, rivers and wetlands, were evaluated, based on local expert knowledge and scientific literature. Results demonstrate that KGDEs contribute considerably to regional biodiversity. The diversity of karst landscapes, combined with the groundwater emergence at springs, leads to exceptional habitat diversity, particularly in arid climates, where KGDEs serve as a refuge for species that could not thrive in the surrounding environment. The most common threats identified among the selected sites are direct human disturbances, such as mass tourism or overfishing, water-quality deterioration and water shortage from aquifer overdraft and/or climate change. Although most of the selected sites are under protection, conservation measures are frequently insufficient. Such shortcomings are often caused by poor data availability, little knowledge on conservation needs of invertebrate species, and conflicts of interest with the local population. For this purpose, it is necessary to raise environmental awareness and promote interdisciplinary research, in order to monitor water quality and quantity in addition to the status of the biocenoses.

Poznavanje terminologije v različnih jezikih je potrebno za pravilno podajanje rezultatov znanstvenega dela, za mednarodno sodelovanje strokovnjakov in za prevajanje strokovnih tekstov. Namen članka je predstaviti tipično kitajsko kraško pokrajino in razložiti termine, ki jih uporabljajo. čeprav se kraško raziskovanje na Kitajskem razvija ločeno od krasoslovja na Zahodu, se v mednarodni kraški terminologiji postopoma uveljavljajo izrazi kitajskega izvora, kot so fengcong, fenglin, shilin in drugi. Vprašanje, kako z vnašanjem novih izrazov v ožjo strokovno javnost, kjer so že uveljavljeni stari termini, ostaja vedno odprto. Včasih je to potrebno, ker ima nov izraz tudi nekoliko obogaten pomen, oziroma združuje več informacij in izboljšuje razumevanje. O primernosti take odločitve naj presodijo nadaljnje razprave, ki morajo izhajati iz poznavanja problema in ne iz sentimentalnosti do izrazov, če so ti imeli do sedaj bolj splošen pomen.  Good knowledge of terminology in different languages is indispensable to be able to present correctly the results of scientific work, for international cooperation of experts and for translating professional texts. Purpose of the present article is to represent the typical Chinese karst landscape and to explain the terms used in the country. Although karst researches in China are carried out separately from the karst-sciences of western countries, terms such as fengcong, fenglin, shilin are enforcing gradually into international karst terminology. Question how to introduce new terms into narrower professional public sphere with old terms already established, is still remaining open. Sometimes this is necessary since a new term is of somehow enriched meaning or is gathering more information and improving the understanding. Appropriateness of such decision should be estimated by further discussions, which should be based upon familiarity with the problem and not upon the sentimentality towards the terms, if these have born more general meaning up to this time.  

Prvega pravega znanstvenega raziskovanja krasa in jam na območju južne Kitajske se je lotil Xu Xiake (1587 - 1641). Kras je proučeval več kot trideset let ter obiskal preko 300 jam. Svoja popotovanja po skoraj polovici ozemlja tedanjega kitajskega cesarstva je opisal v knjigi ≈Xu Xiakejeva potovanja« (≈Xu Xiake youji«), ki je bila prvič objavljena leta 1642. Velja za najzgodnejše razprave o krasu in je napisana v obliki dnevnih zapiskov. Opisal je podzemne reke in jezera, vodne vire, narisal je tlorise nekaterih jam in zabeležil njihove vhode ter opisal različne oblike speleotemov, načine plezanja po jamah in metode raziskovanja jam. Prvi je opisal različne tipe tropskega krasa ter se osredotočil na značilnosti in vzroke nastanka stolpastih vzpetin. V literaturo je vpeljal izraz fēnglín (gozd vrhov). Zato Xu Xiake ni oče moderne speleologije, krasoslovja, geomorfologije in geografije le v kitajskem merilu, temveč tudi v svetovnem.The first real scientific exploration of karst and karst caves in south China was undertaken by Xu Xiake (1587 - 1641). Chinese karst was studied by Xu Xiake for more than thirty years. He described his journeys to almost half of the territory of the Ming dynasty in his book ˝Xu Xiake's travels˝ (˝Xu Xiake youji˝), that was first published in 1642. He dedicated a lot of time to the research of the underground world by describing subterranean rivers and lakes as water resources. He also made ground plans of some caves, marked their entrances and described different shapes of speleothems. He first described different ways of climbing in caves and methods for cave research. Altogether he visited over 300 caves. Xu Xiake first described different types of the tropical karst and focused on the characteristics and reasons of the tower hills origin. He introduced the term fenglin (peak forest), which is still used in the scientific literature. However, he is not only the father of the modern speleology, karstology, geomorphology and geography in the Chinese scale but in a worldwide sense.

Na Krasu je bil od nekdaj največji problem oskrba s kakovostno pitno vodo, ki je omejevala poselitev in gospodarski razvoj območja. Sodobna oskrba ne zagotavlja zadostne količine pitne vode za gospodinjstva in gospodarstvo le na Krasu, temveč jo v poletnem času oddaja celo na Obalo. Oskrba s pitno vodo temelji na črpanju kraške podtalnice iz vrtin pri Klaričih in na dveh izvirih pod Nanosom. Pri snovanju vodne oskrbe kaže v prihodnosti vključiti številne lokalne vodne vire v povezavi s tradicionalno obliko vodne oskrbe. Pri tem ni izključena morebitna uporaba kapnice za potrebe namakanja vrtov, pranje avtomobilov, za komunalne dejavnosti (pranje ulic) in v kmetijstvu ter ponovna uporaba odpadnih voda za tehnološko vodo v industriji.In the past the biggest economic problem on the Kras plateau used to be drinking water supply, which has also been one of the reasons for sparsely populated Kras plateau.Today the Water Supply Company provides drinking water to households and industry on the Kras plateau and the quantity is suffi cient to supply the coastal region in the summer months as well. Water supply is founded on effective karst groundwater pumping near Klariči. Some water is captured from karst springs under Nanos Mountain as well.In water supply planning in future, numerous other local water resources linked to traditional ways of water supply need to be considered. Eventual rainwater usage for garden irrigation or car washing, for communal activity (street washing) or for the needs of farming and purifi ed wastewater usage for industry (as technological water) is not excluded.

Karst aquifers provide drinking water for 10% of the world’s population, support agriculture, groundwater-dependent activities, and ecosystems. These aquifers are characterised by complex groundwater-flow systems, hence, they are extremely vulnerable and protecting them requires an in-depth understanding of the systems. Poor data accessibility has limited advances in karst research and realistic representation of karst processes in large-scale hydrological studies. In this study, we present World Karst Spring hydrograph (WoKaS) database, a community-wide effort to improve data accessibility. WoKaS is the first global karst springs discharge database with over 400 spring observations collected from articles, hydrological databases and researchers. The dataset’s coverage compares to the global distribution of carbonate rocks with some bias towards the latitudes of more developed countries. WoKaS database will ensure easy access to a large-sample of good quality datasets suitable for a wide range of applications: comparative studies, trend analysis and model evaluation. This database will largely contribute to research advancement in karst hydrology, supports karst groundwater management, and promotes international and interdisciplinary collaborations.Measurement(s)hydrographic feature • fluid flow rateTechnology Type(s)digital curationFactor Type(s)geographic location • yearSample Characteristic - Environmentkarst • spring • groundwaterMachine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11336507

Performance criteria play a key role in the calibration and evaluation of hydrological models and have been extensively developed and studied, but some of the most used criteria still have unknown pitfalls. This study set out to examine counterbalancing errors, which are inherent to the Kling–Gupta efficiency (KGE) and its variants. A total of nine performance criteria – including the KGE and its variants, as well as the Nash–Sutcliffe efficiency (NSE) and the modified index of agreement (d1) – were analysed using synthetic time series and a real case study. Results showed that, when assessing a simulation, the score of the KGE and some of its variants can be increased by concurrent overestimation and underestimation of discharge. These counterbalancing errors may favour bias and variability parameters, therefore preserving an overall high score of the performance criteria. As bias and variability parameters generally account for two-thirds of the weight in the equation of performance criteria such as the KGE, this can lead to an overall higher criterion score without being associated with an increase in model relevance. We recommend using (i) performance criteria that are not or less prone to counterbalancing errors (d1, modified KGE, non-parametric KGE, diagnostic efficiency) and/or (ii) scaling factors in the equation to reduce the influence of relative parameters.

Karst areas are characteristic landscapes formed by the dissolution of soluble rocks, whose hydrology is largely influenced by rapid infiltration through the karst massif. These areas are often hotspots of biodiversity, especially for epikarst and cave fauna. The epikarst, the uppermost layer of the unsaturated zone, plays a crucial role in regulating water flow in karst aquifers. The aim of this study was to investigate the extent of microplastic (MP) pollution, its relationship with precipitation and its correlation with copepod populations in karst areas. The study was conducted between April 2021 and October 2022 in the Postojna–Planina karst area in SW Slovenia at surface and underground sampling sites to determine the pathways of MP pollution from the surface to the depth of the karst massif. The results indicate that heavier rainfall flushes out more MP contaminants from the surface and epikarst environment. The transport dynamics of MP pollution are similar to the dynamics of copepods, which are the baseline organisms for the food chain in caves. One MP sample contained only polyamide particles, which could indicate clothing as a possible source of pollution, but the results are inconclusive. With this study, we provide the first insight into the transport of MP pollution from the surface environment to deeper karst massifs.

The karst environment presents a special challenge when it comes to identifying groundwater/surface-water interactions. Existing definitions of areas of regular flooding in karst regions are too general and lack a measurable approach for the determination of flood-liable land. This paper proposes a means of specific definition and quantitative determination of intermittently flooded karst areas, which takes into account the extent, duration and frequency of flooding, and includes the identification of data sources and processing methods. The procedure, involving spatial layers, was developed using a pilot area and tested in three additional areas in Slovenia. The derived definition determines that flood-liable land within karst poljes and intermittent lakes comprise areas where stagnant water or stream overflow is present for at least 10 days/year over a period of 30 years, and these waters have direct contact with groundwater. The results show that the proposed procedure is applicable to areas with different geomorphological settings and to areas where the quantity and quality of available data vary. The study is an example of the practical application of knowledge on karst, as the findings can be used for short-term purposes (mapping flood areas, determination of habitats) and long-term purposes (study of impacts of environmental changes). Attention should be drawn to the lack of available data and the fact that the national networks of hydrological observatories are often too sparse for this purpose. This study raises awareness of these shortcomings and improves the planning or expansion of such a network in collaboration with experts.