scholarly journals Identifying the origin and geochemical evolution of groundwater using hydrochemistry and stable isotopes in the Subei Lake basin, Ordos energy base, Northwestern China

2015 ◽  
Vol 19 (1) ◽  
pp. 551-565 ◽  
Author(s):  
F. Liu ◽  
X. Song ◽  
L. Yang ◽  
Y. Zhang ◽  
D. Han ◽  
...  

Abstract. A series of changes in groundwater systems caused by groundwater exploitation in energy base have been of great concern to hydrogeologists. The research aims to identify the origin and geochemical evolution of groundwater in the Subei Lake basin under the influence of human activities. Water samples were collected, and major ions and stable isotopes (δ18O, δD) were analyzed. In terms of hydrogeological conditions and the analytical results of hydrochemical data, groundwater can be classified into three types: the Quaternary groundwater, the shallow Cretaceous groundwater and the deep Cretaceous groundwater. Piper diagram and correlation analysis were used to reveal the hydrochemical characteristics of water resources. The dominant water type of the lake water was Cl-Na type, which was in accordance with hydrochemical characteristics of inland salt lakes; the predominant hydrochemical types for groundwater were HCO3–Ca, HCO3–Na and mixed HCO3–Ca–Na–Mg types. The groundwater chemistry is mainly controlled by dissolution/precipitation of anhydrite, gypsum, halite and calcite. The dedolomitization and cation exchange are also important factors. Rock weathering is confirmed to play a leading role in the mechanisms responsible for the chemical composition of groundwater. The stable isotopic values of oxygen and hydrogen in groundwater are close to the local meteoric water line, indicating that groundwater is of modern local meteoric origin. Unlike significant differences in isotopic values between shallow groundwater and deep groundwater in the Habor Lake basin, shallow Cretaceous groundwater and deep Cretaceous groundwater have similar isotopic characteristics in the Subei Lake basin. Due to the evaporation effect and dry climatic conditions, heavy isotopes are more enriched in lake water than in groundwater. The low slope of the regression line of δ18O and δD in lake water could be ascribed to a combination of mixing and evaporation under conditions of low humidity. Comparison of the regression line for δ18O and δD showed that lake water in the Subei Lake basin contains more heavily isotopic composition than that in the Habor Lake basin, indicating that lake water in the discharge area has undergone stronger evaporation than lake water in the recharge area. Hydrochemical and isotopic information of utmost importance has been provided to decision makers by the present study so that a sustainable groundwater management strategy can be designed for the Ordos energy base.

2014 ◽  
Vol 11 (5) ◽  
pp. 5709-5745 ◽  
Author(s):  
F. Liu ◽  
X. Song ◽  
L. Yang ◽  
Y. Zhang ◽  
D. Han ◽  
...  

Abstract. A hydrochemical and isotopic study was conducted in Subei Lake Basin, northwestern China, to identify the origin and geochemical evolution of groundwater. Water samples were collected, major ions and stable isotopes (δ18O, δ D) were analyzed. In terms of hydrogeological conditions in study area, groundwater can be classified into three types: the Quaternary groundwater, the shallow Cretaceous groundwater, the deep Cretaceous groundwater. Piper diagram and correlation analysis were used to reveal the hydrochemical characteristics of water resources. The dominant water type of lake water was Na-Cl type, which was controlled by strong evaporation and recharge from overland flow and groundwater; the predominant hydrochemical types for groundwater were Ca-HCO3, Na-HCO3, and mixed Ca · Na · Mg-HCO3 types, the groundwater chemistry is mainly controlled by dissolution/precipitation of anhydrite, gypsum, halite and calcite. The dedolomitization and cation exchange are also important factors. Rock weathering is confirmed to play a leading role in the mechanisms responsible for the chemical compositions of groundwater. The stable isotopic values of oxygen and hydrogen in groundwater are close to the local meteoric water line, showing that groundwater is of meteoric origin. The deep Cretaceous groundwater is depleted in heavy isotopes, compared to shallow Cretaceous groundwater. The hydrogen and oxygen isotopes signatures in deep Cretaceous groundwater may show a paleorecharge effect that the deep Cretaceous groundwater was recharged during a geologic period when the climate was wetter and colder than today. Due to strong evaporation effect and dry climatic conditions, heavy isotopes are more enriched in lake water than groundwater. The hydrochemical and isotopic information of utmost importance has been provided to decision-makers by the present study so that a sustainable water resources management policy could be designed for the Ordos energy base.


2021 ◽  
Vol 54 (1F) ◽  
pp. 44-50
Author(s):  
Qusai Y. Al-Kubaisi

Stable isotopes (2H, 18O) in the water cycle can carry all the information about the movement of water molecules, their ratio different from one place to another in rainfall. Stable isotopes are the function of evaporation, relative humidity, temperature and different longitude, latitude and altitude. On this base. A total of 28 water sample (20 samples were analyzed for major ions and 8 samples for stable isotopes) were collected for two periods to study the origin and the type of groundwater in the area between Lesser Zab and the Tigris river The Results indicated that groundwater samples in the study area are brackish saline water and excessively mineralized water. The average groundwater was classified as Mg-Na-Calcium: Cl-Sulfate for two periods. The groundwater samples represent earth alkali with privilege sulfate and chloride according to the piper diagram. The mean values of 18H and 2O in the groundwater sample are -27.7 and -4.9, respectively for the dry period, and -29.8 and -5.2, respectively, for the wet period. The d-excess varies significantly depending on the humidity and temperature at the vapor source. Isotopic analysis of 2H -18O for groundwater in the study area shows that the origin of groundwater in the study area is of meteoric origin from global source and rain from a local source. The downward shifting of the regression line on the 2H-18O diagram indicates that the samples have undergone evaporation events.


2016 ◽  
Author(s):  
Alexander A. Conti ◽  
◽  
Elizabeth H. Gierlowski-Kordesch

The Mesozoic Hartford Basin, a fault-bounded half-graben in New England, is composed of four sedimentologic units displaying lacustrine, playa, and alluvial conditions separated by three tholeiitic basalt flows. Limited outcrop, however, has restricted analyses across the basin. The Jurassic East Berlin Formation, in particular, crops out only in the southern and northern extents of the basin, exposing the upper 100-118-m of deposits. As a result, a new core analysis across a 600-m-transect of East Berlin rocks has been completed in the central region of the basin, exposing the entire 195-m thickness of the formation for the first time. Cores expose eight 3-m-thick lacustrine mudrock units, the upper six of which are correlative to lake deposits identified in the southern and northern extents of the basin. Additionally, thin chicken-wire evaporites demarcate the lowermost, previously unexposed, lacustrine unit, 7-m beneath a 15-cm-thick tufa horizon. Thin playa deposits and thick sheetflood and Vertisol packages separate these lake sequences over 5-30-m of vertical distance.To supplement these sedimentologic data, and better understand lake geochemistry of the basin during East Berlin time, new biomarker analyses have been applied to each of the eight lacustrine mudrock units for the first time. Biomarker data are useful for determining the lake-basin type, a paleolake classification system derived by Bohacs, Carroll, and others to describe predictable physical and geochemical evolution within rift basins from fluvial facies to over-filled, balance-filled, and under-filled lacustrine facies; subsequently, balance-filled lacustrine facies grade to a terminal fluvial facies during changes in accommodation space through time. While fluvial facies envelope lake deposits within the Hartford Basin, identifying the lake types within the East Berlin has been problematic because of limited exposures. These new sedimentologic and biomarker analyses, however, suggest balance-filled lacustrine conditions at the base of the East Berlin that grade into under-filled conditions upsection. These new biomarker data finally provide definitive evidence for changing lake types during East Berlin time.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1806
Author(s):  
Guillaume Meyzonnat ◽  
Florent Barbecot ◽  
José Corcho Alvarado ◽  
Daniele Luigi Pinti ◽  
Jean-Marc Lauzon ◽  
...  

General and isotopic geochemistry of groundwater is an essential tool to decipher hydrogeological contexts and flow paths. Different hydrogeochemical patterns may result from the inherent physical aquifer heterogeneity, which may go unnoticed without detailed investigations gathered from multilevel or multiple observation wells. An alternative to overcome the frequent unavailability of multiple wellbores at sites is to perform a detailed investigation on the single wellbore available. In this perspective, the aim of this study is to use passive samplers to sequentially collect groundwater at depths in long–screened wellbores. Such investigation is carried out for major ions and stable isotopes compositions (δ2H, δ18O, δ13C) at ten sites in the context of fractured carbonate aquifers of the St. Lawrence Lowlands (Quebec, Canada). The information gathered from the calco–carbonic system, major ions and stable isotopes report poorly stratified and evolved groundwater bodies. Contribution of water impacted by anthropogenic activities, such as road salts pollution and carbon sources from C4 vegetation, when they occur, are even observed at the greatest depths. Such observations suggest quick flow paths and efficient mixing conditions, which leads to significant contributions of contemporary groundwater bodies in the fractured aquifers investigated down to depths of about 100 m. Although physical aquifer investigation reported few and heterogeneously distributed fractures per wellbore, hydrogeochemical findings point to at overall well interconnected fracture networks in the aquifer and high vulnerability of groundwater, even at significant depths.


2013 ◽  
Vol 45 (3) ◽  
pp. 379-390 ◽  
Author(s):  
Anna Maria Szczucińska

The major part of the Polish Plain (central Europe) was shaped during the last glaciation and so far has been considered to be poor in groundwater outflows. The present study aimed to map the groundwater outflows and to analyse their water properties in the Lubuska Upland, western Polish Plain. The mapping of the groundwater outflows was supplemented by hydrochemical analyses (major ions and trace metals) of selected outflows. Altogether, approximately 600 groundwater outflows were recorded, of which 45% were springs. The outflow water discharges ranged from 0.001 to 45 L s−1. Most of them were located at the bottom of the slopes of river valleys. The water was neutral (pH 6.9 to 8.11), with electrical conductivity from 261 to 652 μS cm−1 and average temperature ~10 °C. The most common water type was dominated by bicarbonate, sulphates and calcium ions. The waters often exceeded the quality limits for total Fe and Mn2+. This study revealed that groundwater outflows are a common feature of the areas shaped by former glaciations and are most likely supplied by shallow aquifers.


2009 ◽  
Vol 6 (1) ◽  
pp. 491-514 ◽  
Author(s):  
R. F. Krachler ◽  
R. Krachler ◽  
A. Stojanovic ◽  
B. Wielander ◽  
A. Herzig

Abstract. To date, little is known about the pH-stimulated mineralization of organic matter in aquatic environments. In this study, we investigated biodegradation processes in alkaline waters. Study site is a large shallow soda lake in Central Europe (Neusiedler See/Ferto). The decomposition rate of plant litter was measured as a function of pH by incubating air-saturated lake-water samples in contact with Phragmites litter (leaves) from the littoral vegetation. All samples showed high decomposition rates (up to 32% mass loss within 35 days) and a characteristic two-step degradation mechanism. During the degradation process, the solid plant litter was dissolved forming humic colloids. Subsequently, the humic colloids were mineralized to CO2 in the water column. The decomposition rate was linearly related to pH. Increasing pH values accelerated significantly the leaching of humic colloids as well as the final degradation process. The observed two-step mechanism controls the wetland/lake/air carbon fluxes, since large quantities of humic colloids are currently produced in the reed belt, exported through wind-driven circulations and incorporated into the open lake foodweb. At present, the lake is rapidly shrinking due to peat deposition in the littoral zone, whereas it has been resistant to silting-up processes for thousands of years. In order to investigate the cause of this abrupt change, the chemical composition of the lake-water was measured during 1995–2007. A thorough analysis of these data revealed that major lake-water discharges through the lake's artificial outlet channel led to a decline in salinity and alkalinity. According to our estimates, the lake's original salinity and alkalinity was 70–90% higher compared to the present conditions, with the consequence of substantially lower pH values in the present lake. The observed pH dependence of reed litter biodegradation rates points to a causal connection between low pH values and accumulation of peat in the lake basin. Our results suggest that the pH stimulated remineralisation of organic matter plays a major role in maintaining the long-term integrity of saline lake/wetland systems.


Polar Science ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Yu Hoshina ◽  
Koji Fujita ◽  
Yoshinori Iizuka ◽  
Hideaki Motoyama

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