Community news

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That area of influence of a well is the area surrounding a pumping or recharging well within which the potentiometric surface has been changed [22].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?



Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for hydrological balance (Keyword) returned 6 results for the whole karstbase:
Exploration techniques for karst groundwater resources., 2001, Bakalowicz M.
Porous and fissure aquifers display statistical homogeneity of their physical and hydraulic characteristics on a scale ranging from tens to several hundreds of meters. Such homogeneity is a product of the relatively small spatial variability of these characteristics and creates conditions of general hydraulic continuity throughout the entire saturated zone. Their groundwater resources can be explored by a simple approach, i.e. defining the aquifer geometry from geological data, and determining local hydraulic parameters from pumping tests; finally, the local data are extended to characterise the entire aquifer through regionalizing techniques. However, within the infiltration and saturated zones of carbonate aquifers, karst processes create a peculiar void heterogeneity : voids may reach several meters in diameter and several kilometers in length. These voids are organized in a hierarchic network from the input surface often to a single spring: this is the conduit or drainage network. Therefore the network should be fully characterized prior to assessing the groundwater resources of a karst aquifer and its possible storage capacity, i.e. the network's transmissive or drainage function and its links with storage components (its storage function). Traditionally, speleological exploration is considered the best technique for directly characterizing a drainage network. Unfortunately, this usually gives an incorrect view of the karst aquifer because only a few parts (or none at all) are known when there is no access to the saturated zone. The classical hydrogeological approach is thus unsuitable for assessing karst aquifers. In this context, karst hydrogeologists must adopt the classical approach of physicians and biologists examining living bodies, by characterizing a karst aquifer, its resources and storage by accurate description of the void organization and an analysis of its overall behavior (or functioning) and that of its different parts or organs. With such an approach, a karst aquifer is considered as a living organism composed of different types of organs interlinked by functional relationships. Unlike physicians, hydrogeologists generally have to discover the extent of the body they wish to study (the karst system as a drainage unit, its limits and the boundary conditions). Therefore, as in the field of medicine^ techniques are used for describing the aquifer in bi- or tri-dimensional space (geology, geophysics) and for characterizing its functioning (hydrodynamics, natural tracing, hydrological balance). Moreover, data from these techniques are interpreted in order to propose a diagnosis, i.e. for building a conceptual model of the studied aquifer. In the next step, as in medicine, the conceptual model can be assessed with localized tests, such as artificial tracing and diver exploration for borehole positioning and pumping tests. Methods for interpreting tracing and pumping tests must obviously be adapted to the specific nature of karst, i.e. they cannot be based on classical models whose basic assumptions are never verified in the karstic medium. Finally, karst hydrogeologists have to set up and implement a complex set of techniques for describing the extent and limits of a karst system, exploring its drainage pattern, and analyzing its behaviour. All geoscience disciplines are ultimately required for the comprehensive exploration of groundwater resources in karst aquifers.

Alpine karst waters in Slovenia, 2004, Petrič, Metka

Some basic characteristics of the alpine karst waters in Slovenia are presented. By the method of hydrological balance it was estimated that their groundwater reserves can supply a spring with an average discharge 115 m3/s. According to the comparison between the extent of the alpine karst and the EIONET-SI data base on springs it was stated, that for approximately 1200 alpine karst springs the total capacity (not the average discharge, but the amount of water that can be captured at low waters) is around 15 m3/s. At present only some 25% of these reserves is exploited for the water supply of around 240.000 inhabitants. Due to high vulnerability and different human impacts the quality of these water resources is endangered. Therefore it is necessary to protect them with adequate measures planned on the basis of accurate hydrogeological data. Present level of protection is unsatisfactory, as the water protection decree was accepted only for one quarter of captured springs. Additionally, the expert basis for such decree was prepared for a little less than one fifth of captured springs.

Reversibility of forest conversion impacts on water budgets in tropical karst terrain, 2006, Chandler Dg,
A conceptual model of the control of tropical land use and vegetative cover on bedrock recharge is developed for highly permeable geologic substrates. A case study of water budgets is then developed from field data and simple modeling for upland sites with three different vegetative covers (cropland, intensively grazed pasture and forest regrowth) in Leyte, Philippines. Water budget model results show that annual precipitation is divided primarily between evapotranspiration and overland flow for the pasture, but apportioned more to evapotranspiration and inputs to bedrock storage for the crop and forest sites. Modeled evapotranspiration from the forest (1906 mm) was not sufficiently greater than that for either the crop (1661 mm) or pasture (1476 mm) sites to offset the greater overland flow from those sites. The differences in overland flow are related to depth profiles of soil bulk density, which decreased between crop and forest and increased between crop and pasture, and drainable porosity, which increased between crop and forest and decreased between crop and pasture. Dry season streamflow is assumed to be primarily base flow and dependent on wet season bedrock recharge, which was dramatically lower for the pasture (106 mm) than for the crop (1134 mm) or forest covers (1320 mm), for 2946 mm of rainfall. The results support the premise that for landscapes with adequate storage in bedrock fractures, forest regrowth can increase recharge to perched aquifers, and hence dry season baseflow, relative to cropping and that dramatic reductions in overland flow and increases in dry season baseflow may be achieved by reforestation of compacted pastures. (c) 2005 Elsevier B.V. All rights reserved


Strips of metamorphosed carbonate rocks in a contact-karst area in the Jeseniky Mts, Czech Republic, act as aquifers, draining broad areas of crystalline rocks, mostly phyllites. Significant groundwater resources that are partly used as a water supply are in carbonate rocks. Detailed temperature and conductivity measurements coupled with discharge measurements along all streams in the area demonstrate a relatively quick method to locate virtually all important groundwater outflows from carbonates. Discharge measurements of streams crossing carbonate strips enabled us to locate and quantify the capacity of ponors and losing parts of streams in various water stages. Thanks to a detailed knowledge of losing and gaining parts of streams, we were able to select appropriate profiles to separate catchments with differing hydrologic balances (balanced, gaining, losing). Flow directions in carbonates and recharge and discharge areas were delineated by comparing the specific discharges of individual catchments. Resulting flow directions agree with tracer tests in the area. Our outlined approach can be used in many other areas to locate hidden inflows into streams and to estimate flow between individual small catchments, and it may partly compensate for tracer tests as it allows flow directions to be estimated from hydrological balance and rock geometry.

Pleistocene water intrusions from the Mediterranean and Caspian seas into the Black Sea, 2011, Badertscher S. , Fleitmann D. , Cheng H. , Edwards R. L. , Gö, Ktü, Rk O. M. , Zumbü, Hl A. , Leuenberger M. , Tü, Ysü, Z O.

The hydrological balance of the Black Sea is governed by riverine input and by the exchange with the Mediterranean Sea through the shallow Bosporus Strait. These sources have distinctly different oxygen isotope (δ18O) signatures. Therefore, the δ18O of Black Sea water directly reflects the presence or absence of a connection with the Mediterranean Sea, as well as hydrological changes in the vast watersheds of the Black and Caspian seas1, 2, 3. However, the timing of late to middle Pleistocene water intrusions to the Black Sea is poorly constrained in sedimentary sequences4, 5. Here we present a stacked speleothem δ18O record from Sofular Cave in northern Turkey that tracks the isotopic signature of Black Sea surface water, and thus allows a reconstruction of the precise timing of hydrological shifts of the Black Sea. Our record, which extends discontinuously over the last 670,000 years, suggests that the connection between the Black Sea and Mediterranean Sea has been open for a significant period at least twelve times since 670,000 yr ago, more often than previously suggested4, 5. Distinct minima in the Sofular δ18O record indicate at least seven intervals when isotopically depleted freshwater from the Caspian Sea entered the Black Sea. Our data provide precisely dated evidence for a highly dynamic hydrological history of the Black Sea.

Environmental Hydrogeological Study of Louros watershed, Epirus, Greece, 2012, Konstantina Katsanou

The present study aims to describe and characterize the Ionian zone karst formation concerning the karstification grade of carbonate formations and the development of aquifers, through the hydrogeological study of Louros River drainage basin, considering hydrological, hydrogeological and meteorological data, as well as major, trace element, rare earth element and isotope concentrations. It also aims to investigate basic karst properties such as storativity, homogeneity, infiltration coefficients and the parameters of the Louros basin hydrological balance.

To accomplish this aim daily discharge measurements obtained from Public Power Corporation at the Pantanassa station during the years 1956-1957, along with random discharge measurements from 15 springs along the basin performed by IGME between the years 1979-1989, daily meteorological data from 18 stations and 18 sets of potentiometric surface measurements from 38 sites were compiled. Additionally, chemical analyses on major and trace element concentrations of 42 rock samples and of five sets of water samples from 64 sampling sites, along with fourteen sets of successive periods in order to study the seasonal variation in the chemical composition of 11 springs and REE concentrations of 116 water samples. Moreover isotope ratios from 129 rain samples collected at five different altitudes, 331 samples of surface and groundwater samples, radon measurements on 21 groundwater samples and microbiological on 46 samples of surface and groundwater were evaluated. Daily runoff and random spring discharge missing data were completed applying the SAC-SMA and MODKARST simulation algorithms and the values of these parameters for the duration of the research (2008-2010) were predicted. The accuracy of the predicted values was tested applying statistical methods but also against observed values from in situ measurements performed during the same period (2008-2010).

Louros River drainage basin is located at the southern part of Epirus and covers an area of 953 km2. It is elongated and together with the adjacent basin of River Arachthos they constitute the major hydrographic systems discharging in the Amvrakikos Gulf. The main morphological features of the basin are elongated mountain ranges and narrow valleys, which are the result of tectonic and other geological processes mainly controlled by the limestone-“flysch” alternations. The length of the river’s major channel, which is parallel to the major folding direction (NNW-SSE), is 73.5 km. The mountainous part of the hydrogeological basin covers an area of 400 km2 and its endpoint was set at the Pantanassa station, where discharge measurements are performed. The underground limits of the basin coincides with the surface one, defined by the flysch outcrops at the western margin of the Ziros-Zalongo fault zone to the South, the application of isotope determinations and hydraulic load distribution maps at the North and East.

Geologically, Louros River drainage basin is composed of the Ionian zone formations. Triassic evaporites constitute the base of the zone overlain by a thick sequence of carbonate and clastic sedimentary rocks deposited from the Late Triassic to the Upper Eocene. In more detail, from base to top, the lithostratigraphical column of the zone includes dolomite and dolomitic limestone, Pantokrator limestone, Ammonitico Rosso, Posidonia Shales, Vigla limestone, Upper Senonian limestone, Palaeocene-Eocene limestone and Oligocene “flysch”. The major tectonic features of the regions are folds with their axes trending SW-NE at the northern part and NNW-SSE to NNE-SSW southern of the Mousiotitsa-Episkopiko-Petrovouni fault system and the strike-slip fault systems of Ziros and Petousi.

The evaluation of the daily meteorological data revealed that December is the most humid month of the year followed by January, whereas July and August are the driest months. Approximately 40-45% of the annual precipitation is distributed during the winter time and 30% during autumn. The mean annual precipitation ranges from 897.4 to 2051.8 mm and the precipitation altitude relationship suggests an increased precipitation with altitude at a rate of 84 mm/100 m. The maximum temperature is recorded during August and it may reach 40°C and the minimum during January. The temperature variation with the altitude is calculated at 0.61°C/100 m. The maximum solarity time is 377.8 h, recorded during July at the Arta station. December displays the highest relative humidity with a value of 84.2% recorded again at the Arta station. The highest wind velocity values are recorded at the Preveza station and similar velocities are also recorded at the Ioannina station. The real evapotranspiration in Louros drainage basin ranges between 27-39%. The potential evapotranspiration was calculated from the Ioannina station meteorological data, which are considered more representative for Louros basin, at 785.8 mm of precipitation according to Thornthwaite and at 722.0 mm according to Penman-Monteith.

According to the SAC-SMA algorithm the total discharge (surficial and underground) for the years 2008-2010 ranges between 61-73% of the total precipitation. The algorithm simulates the vertical percolation of rainwater in both unsaturated and saturated zones taking into account 15 parameters including the tension water capacity of the unsaturated zone, the maximum water storage capacity of both unsaturated and saturated zones, the water amount escaping into deeper horizons and not recorded at the basin’s outlet, the percentage of impermeable ground which is responsible for instant runoff, etc. These parameters are correlated to the hydrograph and are recalculated according to it. Two interesting aspects were pointed out from the discharge measurements and the algorithm application. The first is related to the maximum amount of free water, which can be stored at the basic flow of the karstic system, which is very high for the whole basin, reaching 1200 mm of precipitation and the second is the amount of water filtered to the deeper horizons, which reaches 0.098.

The discharge of individual karstic units was simulated applying the specialized MODKARST code. The code, which transforms precipitation to discharge resolving mathematical equations of non-linear flow using the mass and energy balance, successfully completed the time series of available data of spring discharge measurements for the period between the years 2008-2010.

Additionally, a number of useful parameters including spring recharge, delay period between precipitation and discharge, the storage capacity of the discharge area were also calculated by the MODKARST code. These data enabled the calculation of the annual infiltration coefficient for each one of the 15 springs and for the whole basin; the latter was found to range between 38-50% of annual precipitation. The total supply area was estimated approximately at 395 km2, which is consistent with the area of Louros hydrogeological basin calculated from hydrogeological data.

The 18 sets of water table measurements, each one corresponding to a different period, revealed that the aquifers of the intermediate part of Louros basin, which are developed in Quaternary alluvial sediments, are laterally connected to the carbonate formations of the individual karstic spring units, forming a common aquifer with a common water table.

Groundwater flow follows a general N-S direction from the topographic highs to the coastal area with local minor shifts to NE-SW and NW-SE directions. The artificial lake at the position of the Public Power Corporation’s Dam at the south of the region is directly connected to the aquifer and plays an important role in water-level variation. The water table contours display a higher gradient to the southern part due to the decreased hydraulic conductivity of the limestones close to Agios Georgios village. The decreased hydraulic conductivity is believed to be the reason for the development of the homonymous spring although the hydraulic load distributions suggest the extension of the aquifer to the south and a relation to the water level in Ziros Lake, boreholes and the Priala springs. The hydraulic gradient in the broader region ranges between 4-16‰. The absolute water level variation between dry and humid season ranges from 2 m at the South to 15-20 m to the North with an average of 9 m.

The hydrological balance of Louros River mountainous basin according to the aforementioned data is calculated as follows: The total precipitation between the years 2008-2010 ranged between 5.67E+08-9.8E+08 m3 and the discharge at Pantanassa site between 3.47E+08-6.83E+08 m3. The real evapotransiration ranged between 29-39% of the precipitation. The total discharge (runoff and groundwater) accounted for 61-73% of the precipitation, whereas the basic flow due to the percolation ranged between 34-38%. Considering a mean water level variation of 9 m, between the dry and humid season, the water amount constituting the local storage is 2025Ε+07 m3.

Statistical evaluation on spring discharge data and the recession curves analysis revealed three distinct levels with diverse karstic weathering along Louros basin coinciding to the upper, intermediate and low flow of Louros River, respectively. The developed karstic units are generally complex but simple individual units develop as well. The response of spring discharge to the stored water amounts is immediate but with relatively large duration suggesting the storage of large quantities of water and a well-developed system of karstic conduits, which however has not yet met its complete evolution. The karst spring’s units are homogeneous and each one is distinguished from different recession coefficients.

The three levels of flow are also distinguished from the duration curves, which point to individual units upstream, complex units receiving and transmitting water to the adjacent ones in the middle part and complex that only receive water from the upper. This distinguishment is also enhanced by the groundwater’s major ion concentrations, which reveal Ca-HCO3 water-type upstream, along with the isotopic composition at the same part. The prevalent Ca-HCO3-Cl-SO4 water-type in the middle part, the Na-Ca-Cl-SO4 water-type downstream and isotope variation confirms this distinguishment. Moreover, REE variation is also consistent with the three levels. The assumption of relatively large stored water reserves, which contribute to analogous “memory” of spring karstic units, as pointed out by autocorreletion functions is enhanced from SAC-SMA algorithm which premises an increased capacity at the lower zone of basic flow, as well as from the hydrochemical and isotopic composition of groundwater. Monitoring of the seasonal variation in groundwater composition revealed minor variations of hydrochemical parameters and remarkably stable isotopic composition. Both aspects can be explained by the existence of a considerable water body acting as a retarder to external changes.

The crosscorrelation functions suggest a well-developed karstic system, which however has not yet reached its complete maturity also confirmed from field observations. The same conclusion is extracted from the homogeneous evolution at the interval of each karstic unit as demonstrated from recession curves on spring hydrographs.

The results from hydrochemical analyses also revealed the effect of evaporitic minerals and phosphate-rich rocks in groundwater composition and confirmed the hydraulic relationships between surface and groundwater.

The study of the isotopic composition also contributed to exclude the potential connection between the Ioannina and Louros basins, confirmed the meteoric origin of groundwater and revealed the effect of seawater in the chemical composition of few sampling sites.

The microbiological research only revealed minor incidents of contamination and significant attenuation of microorganisms during periods of high discharge.

Results 1 to 6 of 6
You probably didn't submit anything to search for