Karst Groundwater Quality Research Articles

Evaluation and Prediction of Karst Groundwater Quality in Taiyuan Lancun Spring Area

In this paper, on the basis of the research on karst groundwater chemistry characteristics of Lancun spring area, fuzzy comprehensive evaluation method is applied to evaluate the groundwater quality of Lancun spring area, and correlation analysis to predict the trend of groundwater quality. The results show that karst water of Lancun spring area is clean in general, which reached grade I. But in some area where industrial enterprises and towns residents are concentrated, items such as nitrate nitrogen content are relatively high. By 2025, the total hardness and Cl- content of karst water in the majority area of the basin change little, but in several area the total hardness and Cl- content show an increasing trend, but not excessive. Other regions show an increasing trend, but not exceeding standards of drinking water.

The impact of hydrogeochemical processes on karst groundwater quality in arid and semiarid area: a case study in the Liulin spring area, north China

Karst groundwater is the major source of water supply for economic development and drinking water in Liulin spring area, north China. Thus, karst groundwater quality and its variation have aroused wide public concern. The primary hydrogeochemical processes that dominate karst groundwater quality, including dissolution of carbonate rocks and evaporite, mixing, and dedolomitization, are analyzed by hydrogeochemical method in combination with multivariate statistical theory and computer simulation technology. The results show that the redox state of groundwater environment transforms gradually from oxidation state to reducing state with increasing temperature and total dissolved solids (TDS) and decreasing pH value along flow path. The hydrogeochemical types of groundwater range from HCO3-Ca·Mg to Cl·SO4-Na. The Ca2+, Mg2+, and HCO3 − in karst groundwater mainly originate from dissolution of calcite and dolomite. Dissolution of calcite occurs in infiltration of rainfall into soils and unsaturated zones and then reaches to saturation before arriving groundwater level. Though saturation index of dolomite (SID) is greater than 0 in most of the samples, dolomite still dissolves along flow path due to the dedolomitization. The SO4 2− derives basically from the dissolution of gypsum rather than oxidation of pyrite. The dissolution of gypsum causes dedolomitization that increases the concentrations of Ca2+, Mg2+, and SO4 2− while the concentration of HCO3 − has smaller changes. The concentrations of Na+ and Cl− are mainly controlled by dissolution of halite. The enrichment of Na+ relative to Cl− in most samples may result from leakage of surface water enriched Na+ and dissolution of mirabilte fragments.

Groundwater quality in karst regions in the Philippines

Groundwater in karst regions in the Philippines is inhabited by a diverse yet unique aquatic fauna. While this habitat is threatened by anthropogenic disturbances, basic physicochemical information is lacking. Here, we provide the first report of karst groundwater quality based on the characterization and assessment of samples collected from caves. Water samples from seven islands (Bohol, Calicoan, Luzon, Mindanao, Negros Oriental, Panglao, and Samar) were analyzed in order to obtain baseline information about and assess the environmental status of groundwater in karst areas. Although most of the sites showed no evidence of anthropogenic disturbance, excessive amounts of NO2−, NO3−, and Cl− were detected in the samples from a few areas, particularly Panglao Island, Bohol. These pollutants likely originate from human-related activities such as the use of water treatment chemicals, detergents, and bleach, as well as the leakage of septic tanks. Further investigations and in-depth studies aimed at clearly understanding the dynamics of the karst groundwater, thus preventing the aggravation of problems with the groundwater in the future, are highly recommended.

Combinatorial analysis on spatial information statistics for the karst water environment in Guiyang, China

The karst groundwater system is extremely vulnerable and easily contaminated by human activities. To understand the spatial distribution of contaminants in the groundwater of karst urban areas and contributors to the contamination, this paper employs the spatial information statistics analysis theory and method to analyze the karst groundwater environment in Guiyang City. Based on the karst groundwater quality data detected in 61 detection points of the research area in the last three years, we made Kriging evaluation isoline map with some ions in the karst groundwater, such as SO42−, Fe3+, Mn2+ and F−, analyzed and evaluated the spatial distribution, extension and variation of four types of ions on the basis of this isoline map. The results of the analysis show that the anomaly areas of SO42−, Fe3+, Mn2+, F− and other ions are mainly located in Baba’ao, Mawangmiao and Sanqiao in northwestern Guiyang City as well as in its downtown area by reasons of the original non-point source pollution and the contamination caused by human activities (industrial and domestic pollution).

The use of environmental isotopic (C, Sr, S) and hydrochemical tracers to characterize anthropogenic effects on karst groundwater quality: A case study of the Shuicheng Basin, SW China

Rapidly increasing populations, and associated intensification of agriculture, urbanization and industrialization, place increased demands on water resources and increased likelihood of pollution in many areas of the world. The Shuicheng Basin, southwestern China, is one such area and in order to understand water–rock interactions (carbonate dissolution) and anthropogenic impacts on groundwater quality in this karstic landform-dominated area, chemical as well as C, Sr and S isotopic compositions of groundwater (spring and well) and surface water (river) were measured during and following rainy seasons. The concentrations of various ions in groundwater were characterized by the dominant cations (Ca2+, Mg2+) and anions (HCO3-, SO42-), which account for more than 80% of the total ion concentration. Strontium isotope ratios (87Sr/86Sr, 0.70760–0.70918, mean 0.70831) and δ13CDIC (−14.2‰ to −8.4‰, mean −10.7‰) indicate that the weathering dissolution of limestone controls Ca2+ and HCO3-. The decrease in δ13CDIC values with increasing concentrations of anthropogenic species (Cl−, NO3- and Na+) shows that the C isotopic composition of DIC can be a useful tracer of contaminants. Chemical compositions, hydrogeological conditions and δ34S analyses showed increasing SO42- concentration, resulting from domestic wastewater, fertilizer applications, atmospheric inputs through coal combustion, and oxidation of sulfide minerals, which typically are abundant in coal formations in the basin. Groundwater from the old downtown, industrial and agricultural areas exhibited high concentrations of Cl−, NO3-, SO42- and Na+, suggesting the groundwater is impacted by significant levels of contamination from human activities.

Management of karst aquifers in Serbia for water supply

Karst aquifers represent one of the main sources of water supply in Serbia. Wide distributions of karstic areas, abundant reserves, and excellent quality of karst groundwater have been the reasons for its extensive use in water supply systems throughout the country. In Serbia, 70 karstic sources have been tapped for centralized water supply, with the assessed minimal capacity exceeding 4.5 m3/s. Most of the large cities of Eastern and Western Serbia currently use karst groundwater for water supply; however, due to unstable flow regime when only natural springflow is tapped, numerous problems arise during the recession period (summer–autumn). During the last two decades, after favorable conditions had been confirmed through hydrogeological survey and feasibility studies, several newly constructed systems for artificial control of karst aquifers (mostly in Eastern Serbia) resulted in significantly improved water supply.

A review of the potential and actual sources of pollution to groundwater in selected karst areas in Slovenia

Abstract. Slovenian karst areas extend over 43% of the country; limestones and dolomites of the Mesozoic era prevail. In Slovenia karst groundwater contributes up to 50% of the total drinking water supply. The quality of water is very high, despite the fact that it is extremely vulnerable to pollution. The present article is a study and a review of the potential and actual sources of pollution to the groundwater in the selected karst aquifers (the Kras, Velika planina and Snežnik plateaus), which differ in their natural characteristics. Unlike the other selected plateaus, the Kras plateau is inhabited. There are several settlements in the area and the industrial, agricultural and traffic activities carried out that represent a serious threat to the quality of karst groundwater. The Velika planina and Snežnik plateaus do not have permanent residents, however there are some serious hazards to the quality of the karst springs arising from sports, tourist, construction and farming activities, as well as from the traffic related to them. Despite relatively favourable conditions for protection, many important karst aquifers and springs are improperly protected in Slovenia. The reason is the lack of knowledge about sustainable water management in karst regions and the confusion in drinking water protection policy.

Karst groundwater basin delineation, Fort Knox, Kentucky

Evaluation of karst groundwater quality concern at Fort Knox Kentucky has required the development of a sitewide karst groundwater flow model and basin delineation investigation. The karst aquifer underlying Fort Knox is developed within approximately 60 m of the St. Louis Limestone and is bounded on three sides by surface streams that represent the local base level. The underlying Salem Limestone acts as a regional aquitard and provides a lower limit to karst aquifer development. The study area covers over 130 km 2 and contains over 200-inventoried karst features. As a part of this investigation, innovative multiple dye trace events were conducted throughout the study area using up to six dyes per event with a total of eight dyes used to conduct 14 dye traces during three seasonal events. Dye trace results, structural and topographic controls, spring characteristics, and normalized base flow were used to establish groundwater basin limits and boundary zones and to develop a conceptual sitewide groundwater flow model. The primary finding of this work indicates sitewide groundwater flow is controlled directly or indirectly by local stratigraphy, geologic structure, and changes in stream levels in the geologic past, and that two groundwater basins dominate the study area, accounting for approximately 80% of measured sitewide groundwater discharge. The findings of this investigation will be used to assess the groundwater contaminant contribution from source areas in individual basins, develop an effective groundwater monitoring program, and guide future groundwater management strategies.

Review of Groundwater Pollution and Protection in Karst Areas

Karst groundwater (the water in a karst aquifer) is a major water resource in many regions of some countries. Water requirements for most of the settlements in the karstic regions are supplied from karst aquifers. Karst environments are also used for the disposal of liquid and solid domestic agricultural, and industrial wastes, which result in karst groundwater pollution. Karst aquifers have specific hydraulic and hydrogeologic characteristics that render them highly vulnerable to pollution from human activities. Karst groundwater becomes polluted more easily and in shorter time periods than water in non-karstic aquifers. Thus, protection measures are required to preserve the quality and quantity of karst groundwater that specifically consider the vulnerability of the karst environment. In order to preserve karst groundwater, the geological, hydrological and hydrogeological characteristics of the karst area must be investigated and information on polluting activities and sources must be collected. Then, a comprehensive protection and control system must be developed consisting of the following six components: (1) develop and implement a groundwater monitoring system, (2) establish critical protection zones, (3) develop proper land use strategies, (4) determine the reasonable development capacity of the karst aquifer, (5) control and eliminate when necessary sources of pollution, (6) increase public awareness of the value and vulnerability of karst aquifers.