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1.
Springs are the only available source of water for domestic and agricultural use in mountainous regions of Dhouli Rao and Kandela in the Sirmaur district of Himachal Pradesh, India. These springs are mainly gravity, contact or fracture and solution tubular (Karst) type. Drying of springs during summer causes much hardship to the inhabitants of this region. Hence, environmental isotopes (2H, 18O, 3H) were employed along with hydrogeochemistry and geomorphology to identify the recharge zones of the drying springs. From the stable isotope data of rainwater, the altitude effect was estimated (?0.3?‰ for δ18O per 100 m elevation) and used to determine the recharge zones of the drying springs (+1,000 to +1,430 m amsl). The geo-morphological setting of the valley indicated that either check dam, contour bunding or levees structures with gabion method of rainwater conservation can be implemented to augment the recharge of the springs.  相似文献   

2.
The groundwater flow system and the flow velocity in the alluvial fan plain of the Hutuo River, China, have been studied, with an emphasis on relating geochemical characteristics and isotopes factors. Seven stretches of one river, six springs and 31 wells, with depths ranging from 0 m (river waters) to 150 m, were surveyed. The groundwater has a vertical two-layer structure with a boundary at about 80–100 m depth, yielding an upper and a lower groundwater layer. The δ18O and δD values range from ?10.56 to ?7.05‰ and ?81.83 to ?59‰, respectively. The groundwater has been recharged by precipitation, and has not been subjected to significant evaporation during infiltration into the aquifer in the upper layer. Using a tritium model, the groundwater flow in the alluvial fan plain showed horizontal flow velocity to be greater than vertical velocity. Groundwater in the upper layer is characterized by Ca–HCO3 type. From the spatial distribution characteristics of the stable isotope and chemical composition of the groundwater, agricultural irrigation was considered to have an influence on the aquifer by causing excessive groundwater abstraction and irrigation return.  相似文献   

3.
Conventional hydrogeochemical data and environmental stable isotopes are used to identify the recharge sources and the water–rock interactions in the groundwater-flowing direction within the multilayer groundwater system of the Sulin coal-mining district in the north Anhui province in China. δD and δ 18O of groundwater in the mining district decrease along the groundwater-flowing direction in the recharge areas, yet in the runoff or discharge areas, they rise and fall along average δ values (δ 18O = ?8.68 ‰, δD = ?67.4 ‰), which are lower than average δ values of local atmospheric precipitation (δ 18O = ?7.80 ‰, δD = ?52.4 ‰). Principal component analysis is used to analyze the conventional hydrogeochemical data (K+ + Na+, Mg2+, Ca2+, Cl?, SO4 2?, HCO3 ?, CO3 2?) in the groundwater. The first and second principal components have large variance contributions, and represent “pyrite oxidation or groundwater hardening” and “desulfurization or cation exchange and adsorption,” respectively. From conventional hydrogeochemical data and environmental stable isotopes, it is demonstrated that groundwater of the Sulin coal-mining district is characterized by a mixing type, which is confirmed by three recharge end-members: fresh groundwater, leaching groundwater, and retained groundwater. By means of a sample dot-encompassed triangle in the scatter diagram of load scores for Component 1–Component 2, whose vertexes stand for the three end-members, a model for calculating groundwater mixing ratio is established and applied successfully to the evaluation and management of groundwater hazards in the coal-mining districts.  相似文献   

4.
The hydrogeochemistry and isotope geochemistry of groundwater from 85 wells in fractured dolomite aquifers of Central Slovenia were investigated. This groundwater represents waters strongly influenced by chemical weathering of dolomite with an average of δ13CCARB value of +2.2 ‰. The major groundwater geochemical composition is HCO3 ? > Ca2+ > Mg2+. Several differences in hydrogeochemical properties among the classes of dolomites were observed when they were divided based on their age and sedimentological properties, with a clear distinction of pure dolomites exhibiting high Mg2+/Ca2+ ratios and low Na+, K+ and Si values. Trace element and nutrient concentrations (SO4 2?, NO3 ?) were low, implying that karstic and fractured dolomite aquifers are of good quality to be used as tap water. Groundwater was generally slightly oversaturated with respect to calcite and dolomite, and dissolved CO2 was up to 46 times supersaturated relative to the atmosphere. The isotopic composition of oxygen (δ18OH2O), hydrogen (δDH2O) and tritium ranged from ?10.3 to ?8.4 ‰, from ?68.5 to ?52.7 ‰ and from 3.5 TU to 10.5 TU, respectively. δ18O and δD values fell between the GMWL (Global Meteoric Water Line) and the MMWL (Mediterranean Meteoric Water Line) and indicate recharge from precipitation with little evaporation. The tritium activity in groundwater suggests that groundwater is generally younger than 50 years. δ13CDIC values ranged from ?14.6 to ?9.3 ‰ and indicated groundwater with a contribution of degraded organic matter/dissolved inorganic carbon in the aquifer. The mass balances for groundwater interacting with carbonate rocks suggested that carbonate dissolution contributes from 43.7 to 65.4 % and degradation of organic matter from 34.6 to 56.3 %.  相似文献   

5.
The Xiangxi River basin, South China, is a steep terrane with well-developed karst features and an important Cambrian-Ordovician aquifer. Meteoric water in this mountainous area features a mean δ18O elevation gradient of –2.4?‰/km. This gradient was used to estimate mean recharge elevations of 760 m for Shuimoxi (SMX) spring, 1,060 m for Xiangshuidong (XSD) spring, and 1,430 m for drill hole ZK03, indicating multiple flow paths in the Cambrian-Ordovician karst aquifer. Mean residence times of 230 and 320 days and ～2 years were estimated for these features, respectively, using the damped running average model that predicts the isotopic variations in groundwater from those in precipitation. Groundwater in the regional karst flow system has the longest residence time, the highest recharge elevation, the longest flow paths, the lowest addition of anthropogenic components, and the greatest amount of water–rock interaction as indicated by its higher dissolved solids, Mg2+ concentrations and Mg/Ca ratios than the springs. In contrast, the local and shallow karst flow systems respond rapidly to recharge events. Artificial tracer tests prove that these shallow karst systems can also quickly transmit anthropogenic contaminants, indicating that they are highly vulnerable to human impacts, which include the enrichment of NO3 –. The intensity of water–rock interaction and groundwater vulnerability are mainly determined by the structure and dynamics of the multiple karst flow systems.  相似文献   

6.
The recharge altitude estimation of thermal springs from northern and eastern Morocco using 18O and 2H contents requires the definition of regional isotopic altitudinal gradients (?0.25‰ for 100 m for the Rif and ?0.30‰ for the East) and the calculation of residence time using 14C. The altitudes of emergence vary widely between 170 and 1040 m under the altitude of the recharge areas. The 18O and 2H compositions of palaeowaters (>10000 yr BP) indicate two effects, altitude and palaeoclimate. To cite this article: A. Winckel et al., C. R. Geoscience 334 (2002) 469–474.  相似文献   

7.
In order to address the problem of realistic assessment of groundwater potential and its sustainability, it is vital to study the recharge processes and mechanism of groundwater flow in fractured hard rocks, where inhomogeneties and discontinuities have a dominant role to play. Wide variations in chloride, δ18O and 14C concentrations of the studied groundwaters observed in space and time could only reflect the heterogeneous hydrogeological setting in the fractured granites of Hyderabad (India). This paper, based on the observed isotopic and environmental chloride variations of the groundwater system, puts forth two broad types of groundwaters involving various recharge processes and flow mechanisms in the studied granitic hard rock aquifers. Relatively high 14C ages (1300 to ～6000 yr B.P.), δ18O content (?3.2 to ?1.5‰) and chloride concentration (<100 mg/l) are the signatures that identified one broad set of groundwaters resulting from recharge through weathered zone and subsequent movement through extensive sheet joints. The second set of groundwaters possessed an age range Modern to ～1000 yr B.P., chloride in the range 100 to ～350 mg/l and δ18O from ?3.2 to +1.7‰. The δ18O enrichment and chloride concentration, further helped in the segregation of the second set of groundwaters into three sub-sets characterized by different recharge processes and sources. Based on these processes and mechanisms, a conceptual hydrogeologic model has evolved suggesting that the fracture network is connected either to a distant recharge source or to a surface reservoir (evaporating water bodies) apart from overlying weathered zone, explaining various resultant groundwaters having varying 14C ages, chloride and δ18O concentrations. The surface reservoir contribution to groundwater is evaluated to be significant (40 to 70%) in one subset of groundwaters. The conceptual hydrogeologic model, thus evolved, can aid in understanding the mechanism of groundwater flow as well as migration of contaminants to deep groundwater in other fractured granitic areas.  相似文献   

8.
The hydrogeochemical and isotopic evolution of groundwaters in the Mio–Pliocene sands of the Complexe Terminal (CT) aquifer in central Algeria are described. The CT aquifer is located in the large sedimentary basin of the Great Oriental Erg. Down-gradient groundwater evolution is considered along the main representative aquifer cross section (south–north), from the southern recharge area (Tinrhert Plateau and Great Oriental Erg) over about 700 km. Groundwater mineralisation increases along the flow line, from 1.5 to 8 g l?1, primarily as a result of dissolution of evaporite minerals, as shown by Br/Cl and strontium isotope ratios. Trends in both major and trace elements demonstrate a progressive evolution along the flow path. Redox reactions are important and the persistence of oxidising conditions favours the increase in some trace elements (e.g. Cr) and also NO3 ?, which reaches concentrations of 16.8 mg l?1 NO3-N. The range in 14C, 0–8.4 pmc in the deeper groundwaters, corresponds with late Pleistocene recharge, although there then follows a hiatus in the data with no results in the range 10–20 pmc, interpreted as a gap in recharge coincident with hyper-arid but cool conditions across the Sahara; groundwater in the range 24.7–38.9 pmc signifies a distinct period of Holocene recharge. All δ18O compositions are enriched relative to deuterium and are considered to be derived by evaporative enrichment from a parent rainfall around ?11‰ δ18O, signifying cooler conditions in the late Pleistocene and possibly heavy monsoon rains during the Holocene.  相似文献   

9.
In this study, hydrochemical and isotope investigations were conducted in the Yanqi Basin to determine the chemical composition, and to gain insight into the groundwater recharge process in the Yanqi Basin. It mainly used hydrochemistry, environmental isotopes, and a series of comprehensive data interpretation, e.g., statistics, ionic ratios, and Piper diagram to obtain a better understanding of the functioning of the system. The following hydrochemical processes were identified as the main factors controlling the water quality of the groundwater system: weathering of silicate minerals, dissolution, ion exchange, and to a lesser extent, evaporation, which seemed to be more pronounced down gradient of the flow system. As groundwater flows from the recharge to discharge areas, chemical patterns evolve in the order of Ca2+–HCO3 ?, Ca2+/Mg2+–HCO3 ? to Ca2+–Mg2+–Cl?–SO4 2?, Na+–K+–Cl?–SO4 2? and Na+–Cl? according to lithology. The environmental isotope (δ 18O, δ 2H, 3H) measurements further revealed that precipitation was the main recharge source for the groundwater system; some local values indicated high levels of evaporation. Tritium and CFC analysis were used to estimate the ages of the different groundwater; the tritium values of the groundwater samples varied from 2.82 to 29.7 TU. The age of the groundwater at depths of <120 m is about 30–50 years. CFC values obtained for six samples to determine groundwater age; the age of the groundwater is about 20–50 years.  相似文献   

10.
Oxygen isotopes and strontium concentrations were used as geochemical tracers to discern the sources of water to Celestún Lagoon, a small subtropical estuary on the western side of the Yucatán Peninsula of Mexico. Celestún Lagoon is underlain by karstified limestone with numerous locations where groundwater is observed discharging directly to the lagoon. In this study, samples of groundwater, lagoon surface water, and seawater (SW) were collected in April 2008 and June 2009 and analyzed for salinity, stable isotopes of oxygen, and strontium (Sr2+) concentrations. These geochemical tracers were used in two tertiary mixing models to calculate the relative ratio inputs of fresh groundwater, brackish groundwater, and SW to the lagoon. Two sources of groundwater were found to contribute to the surface water in the lagoon; one fresh and the other brackish with an average salinity of 19 psu. The fresh groundwater had an oxygen isotopic signature (δ18O) and strontium concentration (Sr2+) of δ18O?=?-3.30‰ and Sr2+?=?0.03 mmol/l, respectively. The brackish groundwater observed in the northern end of the lagoon add a dissimilar oxygen isotopic signature and Sr2+ concentration of δ18O?=?3.01‰ and Sr2+?=?0.12 mmol/l, respectively. Local SW had an isotopic oxygen signature and Sr2+ concentration between the two fresher sources (δ18O?=?1.40‰, Sr2+?=?0.09 mmol/l). The lagoonwide results of the two tracer mixing models (δ18O and Sr2+) agreed well (within 5 %) and indicated a ratio of brackish groundwater–fresh groundwater– SW of 31 %–26 %–43 % (±5 %) for the Sr2+ model and 35 %–25 %–40 % (± 5 %) for the δ18O model. Brackish groundwater is dominant in the northern portion of the lagoon, while SW dominates the southern portion. Fresh groundwater discharge is a significant contributor of water along the entire eastern boundary of the lagoon where mangrove forests are the dominant vegetation.  相似文献   

11.
This paper summarizes a new outlook on the conceptual model of Melgaço–Messegães CO2-rich cold (≈18 °C) mineral water systems, issuing in N of Portugal, based on their isotopic (2H, 3H, 13C, 14C and 18O) and geochemical features. Stable isotopes indicate the meteoric origin of these CO2-rich mineral waters. Based on the isotopic fractionation with the altitude, a recharge altitude between 513 up to 740 m a.s.l. was estimated, corroborating the tritium results. The lowest 3H content (0 TU) is found in the groundwater samples with the highest mineralization. The mineral waters circulation are mainly related to a granitic and granodioritic environment inducing two different groundwater types (Ca/Na–HCO3 and Na/Ca–HCO3), indicating different underground flow paths. Calcium dissolution is controlled by hydrolysis of rock-matrix silicate minerals (e.g. Ca-plagioclases) and not associated to anthropogenic sources. The shallow dilute groundwaters exhibit signatures of anthropogenic origins (e.g. NO3) and higher Na/Ca ratios. The stable isotopes together with the geochemistry provided no indication of mixing between the regional shallow cold dilute groundwater and mineral water systems. The heavy isotopic signatures identified in the δ13C data (δ13C = 4.7 ‰, performed on the total dissolved inorganic carbon (TDIC) of CO2-rich mineral waters) could be derived from a deep-seated (upper mantle) source or associated to methanogenesis (CH4 source). The negligible 14C content (≈2 pmC) determined in the TDIC of the mineral waters, corroborates the hypothesis of a mantle-derived carbon source to the mineral groundwater systems or dissolution of carbonate layers at depth.  相似文献   

12.
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13.
The Quaternary coastal plain aquifer down gradient of the Wadi Watir catchment is the main source of potable groundwater in the arid region of south Sinai, Egypt. The scarcity of rainfall over the last decade, combined with high groundwater pumping rates, have resulted in water-quality degradation in the main well field and in wells along the coast. Understanding the sources of groundwater salinization and amount of average annual recharge is critical for developing sustainable groundwater management strategies for the long-term prevention of groundwater quality deterioration. A combination of geochemistry, conservative ions (Cl and Br), and isotopic tracers (87/86Sr, δ81Br, δ37Cl), in conjunction with groundwater modeling, is an effective method to assess and manage groundwater resources in the Wadi Watir delta aquifers. High groundwater salinity, including high Cl and Br concentrations, is recorded inland in the deep drilled wells located in the main well field and in wells along the coast. The range of Cl/Br ratios for shallow and deep groundwaters in the delta (∼50–97) fall between the end member values of the recharge water that comes from the up gradient watershed, and evaporated seawater of marine origin, which is significantly different than the ratio in modern seawater (228). The 87/86Sr and δ81Br isotopic values were higher in the recharge water (0.70,723 < 87/86Sr < 0.70,894, +0.94 < δ81Br < +1.28‰), and lower in the deep groundwater (0.70,698 < 87/86Sr < 0.70,705, +0.22‰ < δ81Br < +0.41‰). The δ37Cl isotopic values were lower in the recharge water (−0.48 < δ37Cl < −0.06‰) and higher in the deep groundwater (−0.01 < δ37Cl < +0.22‰). The isotopic values of strontium, chloride, and bromide in groundwater from the Wadi Watir delta aquifers indicate that the main groundwater recharge source comes from the up gradient catchment along the main stream channel entering the delta. The solute-weighted mass balance mixing models show that groundwater in the main well field contains 4–10% deep saline groundwater, and groundwater in some wells along the coast contain 2–6% seawater and 18–29% deep saline groundwater.A three-dimensional, variable-density, flow-and-transport SEAWAT model was developed using groundwater isotopes (87Sr/86Sr, δ37Cl and δ81Br) and calibrated using historical records of groundwater level and salinity. δ18O was used to normalize the evaporative effect on shallow groundwater salinity for model calibration. The model shows how groundwater salinity and hydrologic data can be used in SEAWAT to understand recharge mechanisms, estimate groundwater recharge rates, and simulate the upwelling of deep saline groundwater and seawater intrusion. The model indicates that most of the groundwater recharge occurs near the outlet of the main channel. Average annual recharge to delta alluvial aquifers for 1982 to 2009 is estimated to be 2.16 × 106 m3/yr. The main factors that control groundwater salinity are overpumping and recharge availability.  相似文献   

14.
Annual abstraction of 2.6?×?109 m3 of groundwater in the 53,000 km2 Konya Closed Basin of central Turkey has caused a head decline of 1 m/year over the last few decades. Therefore, understanding the hydrogeology of this large endorheic basin, in a semi-arid climate, is important to sustainable resource management. For this purpose, the groundwater’s radiocarbon age distribution has been investigated along a 150-km transect parallel to regional flow. Results show that the groundwater ranges in age from Recent at the main recharge area of the Taurus Mountains in the south, to about 40,000 years around the terminal Salt Lake located in the north. In this predominantly confined flow system, radiocarbon ages increase linearly by distance from the main recharge area and are in agreement with the hydraulic ages. The mean velocity of regional groundwater flow (3 m/year) is determined by the rate of regional groundwater discharge into the Salt Lake. Calcite dissolution, dedolomitization and geogenic carbon dioxide influx appear to be the dominant geochemical processes that determine the carbon isotope composition along the regional flow path. The groundwater’s oxygen-18 content indicates more humid and cooler paleorecharge. A maximum drop of 5°C is inferred for the past recharge temperature.  相似文献   

15.
On the basis of the isotopic composition of water in the northern part of Epirus, Greece, from springs at different altitudes with well-defined recharge areas, the altitude effect on the δ18O value of groundwater is –0.142±0.003ö (100?m)–1 and is uniform over the entire study area. Using the δ18O composition of surface water and groundwaters, the contribution of Ioannina Lake and the channel draining the lake water to the Kalamas River to the recharge of springs and boreholes was confirmed and quantitatively defined. In contrast, the Voidomatis and Vikos Rivers are not sources for recharge of the big springs along their banks. However, water from the Aoos River does replenish the aquifer in the unconsolidated deposits underlying the plain of Konitsa. In addition, limestones of Senonian–Late Eocene ages, dolomites, and limestones of the "Vigles" facies are hydraulically interconnected, and the limestones of the "Pantokrator" facies are hydraulically isolated from the other carbonate formations.  相似文献   

16.
Hydrochemical and isotope data in conjunction with hydraulic head and spring discharge observations were used to characterize the regional groundwater flow dynamics and the role of the tectonic setting in the Gidabo River Basin, Ethiopian Rift. Both groundwater levels and hydrochemical and isotopic data indicate groundwater flow from the major recharge area in the highland and escarpment into deep rift floor aquifers, suggesting a deep regional flow system can be distinguished from the shallow local aquifers. The δ18O and δ2H values of deep thermal (≥30 °C) groundwater are depleted relative to the shallow (<60 m below ground level) groundwater in the rift floor. Based on the δ18O values, the thermal groundwater is found to be recharged in the highland around 2,600 m a.s.l. and on average mixed with a proportion of 30 % shallow groundwater. While most groundwater samples display diluted solutions, δ13C data of dissolved inorganic carbon reveal that locally the thermal groundwater near fault zones is loaded with mantle CO2, which enhances silicate weathering and leads to anomalously high total dissolved solids (2,000–2,320 mg/l) and fluoride concentrations (6–15 mg/l) exceeding the recommended guideline value. The faults are generally found to act as complex conduit leaky barrier systems favoring vertical mixing processes. Normal faults dipping to the west appear to facilitate movement of groundwater into deeper aquifers and towards the rift floor, whereas those dipping to the east tend to act as leaky barriers perpendicular to the fault but enable preferential flow parallel to the fault plane.  相似文献   

17.
In the cool temperate region of South Korea, oxygen and hydrogen isotopes of groundwater, lake water, and precipitation were studied to determine the season of groundwater recharge. All the groundwater samples, irrespective of season, on δ18O–δ2H scale plotted along the summer precipitation, suggesting summer precipitation largely modulates recharge. The deuterium excess values of groundwater (d-excess) show clear seasonal difference, higher in winter (> 18‰) and lower in summer (< 10‰). And its resemblance to the summer precipitation d-excess value further suggests dominant role of summer precipitation in groundwater recharge. Based on the mass balance equation, with end-member d-excess values of seasonal precipitation and groundwater as input variables, groundwater is composed of 66% summer and 34% winter precipitation. Despite the study area being heavily forested, summer rainfall contribution higher than winter suggests that evapotranspiration effect is minimal in the region; may be due to thin sand–gravel-based porous soil overlying highly weathered granitic rock system.  相似文献   

18.
Understanding the transference of water resources within hydrogeological systems, particularly in coastal aquifers, in which groundwater discharge may occur through multiple pathways (through springs, into rivers and streams, towards the sea, etc.), is crucial for sustainable groundwater use. This research aims to demonstrate the usefulness of the application of conventional recharge assessment methods coupled to isotopic techniques for accurately quantifying the hydrogeological balance and submarine groundwater discharge (SGD) from coastal carbonate aquifers. Sierra Almijara (Southern Spain), a carbonate aquifer formed of Triassic marbles, is considered as representative of Mediterranean coastal karst formations. The use of a multi-method approach has permitted the computation of a wide range of groundwater infiltration rates (17–60%) by means of direct application of hydrometeorological methods (Thornthwaite and Kessler) and spatially distributed information (modified APLIS method). A spatially weighted recharge rate of 42% results from the most coherent information on physiographic and hydrogeological characteristics of the studied system. Natural aquifer discharge and groundwater abstraction have been volumetrically quantified, based on flow and water-level data, while the relevance of SGD was estimated from the spatial analysis of salinity, 222Rn and the short-lived radium isotope 224Ra in coastal seawater. The total mean aquifer discharge (44.9–45.9 hm3 year?1) is in agreement with the average recharged groundwater (44.7 hm3 year?1), given that the system is volumetrically equilibrated during the study period. Besides the groundwater resources assessment, the methodological aspects of this research may be interesting for groundwater management and protection strategies in coastal areas, particularly karst environments.  相似文献   

19.
Geochemistry and environmental tracers were used to understand groundwater resources, recharge processes, and potential sources of contamination in the Rio Actopan Basin, Veracruz State, Mexico. Total dissolved solids are lower in wells and springs located in the basin uplands compared with those closer to the coast, likely associated with rock/water interaction. Geochemical results also indicate some saltwater intrusion near the coast and increased nitrate near urban centers. Stable isotopes show that precipitation is the source of recharge to the groundwater system. Interestingly, some high-elevation springs are more isotopically enriched than average annual precipitation at higher elevations, indicating preferential recharge during the drier but cooler winter months when evapotranspiration is reduced. In contrast, groundwater below 1,200 m elevation is more isotopically depleted than average precipitation, indicating recharge occurring at much higher elevation than the sampling site. Relatively cool recharge temperatures, derived from noble gas measurements at four sites (11–20 °C), also suggest higher elevation recharge. Environmental tracers indicate that groundwater residence time in the basin ranges from 12,000 years to modern. While this large range shows varying groundwater flowpaths and travel times, ages using different tracer methods (14C, 3H/3He, CFCs) were generally consistent. Comparing multiple tracers such as CFC-12 with CFC-113 indicates piston-flow to some discharge points, yet binary mixing of young and older groundwater at other points. In summary, groundwater within the Rio Actopan Basin watershed is relatively young (Holocene) and the majority of recharge occurs in the basin uplands and moves towards the coast.  相似文献   

20.
The study area is located in the border of the high and low folded zone having a semi-arid climate area. This study initiated in 2009–2010, deals essentially with the investigation of the stable isotope (18O and deuterium 2H) as well as radioactive isotope represented by tritium 3H in rain, carbonate springs, intergranular aquifer, and surface water in order to investigate the source and relative ages of the groundwater and to show the influence of the altitude variations of the isotope composition. In this study and for the first time in the area, a local meteoric water line have been drawn with an empirical formula δ 2H?=?7.7δ 18O?+?14.4. The δ 18O–altitude effect was determined using isotopic data for several samples taken from groundwater and surface water; it was approximated at ?0.79?‰/100 m for the entire area of the study. The output of the tritium concentrations in the springs and water well samples revealed to the conclusion that the values closely resembles to the present time tritium concentration in precipitation.  相似文献   

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