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| Author | Sarker, M.M.R.; Van Camp, M.; Islam, M.; Ahmed, N.; Walraevens, K. | ||||
Title  |
Hydrochemistry in coastal aquifer of southwest Bangladesh : origin of salinity | Type | Journal Article | ||
| Year | 2018 | Publication | Environmental Earth Sciences | Abbreviated Journal | |
| Volume | 77 | Issue | 2 | Pages | 20 |
| Keywords | Hydrochemistry,Stable isotope,Seawater intrusion,Coastal aquifer,Bangladesh,DAR-ES-SALAAM,SEAWATER INTRUSION,DELTA PLAIN,GROUNDWATER,DRINKING,TANZANIA,DROUGHT,COMPLEX | ||||
| Abstract | In the coastal region of Bangladesh, groundwater is mainly used for domestic and agricultural purposes, but salinization of many groundwater resources limits its suitability for human consumption and practical application. This paper reports the results of a study that has mapped the salinity distribution in different aquifer layers up to a depth of 300 m in a region bordering the Bay of Bengal based on the main hydrochemistry and has investigated the origin of the salinity using Cl/Br ratios of the samples. The subsurface consists of a sequence of deltaic sediments with an alternation of more sandy and clayey sections in which several aquifer layers can be recognized. The main hydrochemistry shows different main water types in the different aquifers, indicating varying stages of freshening or salinization processes. The most freshwater, soft NaHCO3-type water with Cl concentrations mostly below 100 mg/l, is found in the deepest aquifer at 200-300 m below ground level (b.g.l.), in which the fresh/saltwater interface is pushed far to the south. Salinity is a main problem in the shallow aquifer systems, where Cl concentrations rise to nearly 8000 mg/l and the groundwater is mostly brackish NaCl water. Investigation of the Cl/Br ratios has shown that the source of the salinity in the deep aquifer is mixing with old connate seawater and that the saline waters in the more shallow aquifers do not originate from old connate water or direct seawater intrusion, but are derived from the dissolution of evaporite salts. These must have been formed in a tidal flat under influence of a strong seasonal precipitation pattern. Long dry seasons with high evaporation rates have evaporated seawater from inundated gullies and depressions, leading to salt precipitation, while subsequent heavy monsoon rains have dissolved the formed salts, and the solution has infiltrated in the subsoil, recharging groundwater. | ||||
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| ISSN | 1866-6280 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | THL @ christoph.kuells @ Sarker2018 | Serial | 194 | ||
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| Author | Kim, Y.; Lee, K.-S.; Koh, D.-C.; Lee, D.-H.; Lee, S.-G.; Park, W.-B.; Koh, G.-W.; Woo, N.-C. | ||||
| Title |
Hydrogeochemical and isotopic evidence of groundwater salinization in a coastal aquifer: a case study in Jeju volcanic island, Korea | Type | Journal Article | ||
| Year | 2003 | Publication | Journal of Hydrology | Abbreviated Journal | |
| Volume | 270 | Issue | 3 | Pages | 282-294 |
| Keywords | Jeju volcanic island, Coastal aquifer, Groundwater salinization, Hydrogeochemistry, Environmental isotopes, Mixing process | ||||
| Abstract | In order to identify the origin of saline groundwater in the eastern part of Jeju volcanic island, Korea, a hydrogeochemical and isotopic study has been carried out for 18 observation wells located in east and southeast coastal regions. The total dissolved solid contents of groundwaters are highly variable (77–21,782mg/l). Oxygen, hydrogen, sulfur, and strontium isotopic data clearly show that the saline water results from mixing of groundwater with seawater. Strontium isotopic compositions and Br/Cl and I/Cl ratios strongly suggest that the source of salinity is modern seawater intrusion. Hydrogeochemical characteristics based on bivariate diagrams of major and minor ions show that changes in the chemical composition of groundwater are mainly controlled by the salinization process followed by cation-exchange reactions. The highly permeable aquifers at the east coastal region are characterized by low hydraulic gradient and discharge rate and high hydraulic conductivity as compared with other regions. These properties enhance the salinization of groundwater observed in the study area. Based on the Cl, Br, and δ18O data, seawater was determined to have intruded inland some 2.5km from the coastline. Considering the poor correlation of sampling depth and Cl concentrations observed, the position of seawater-freshwater interface is not uniformly distributed in the study area, due to heterogeneities of the basaltic aquifers. | ||||
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| ISSN | 0022-1694 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | THL @ christoph.kuells @ Kim2003282 | Serial | 172 | ||
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| Author | Liu, Y.; Jin, M.; Wang, J. | ||||
| Title |
Insights into groundwater salinization from hydrogeochemical and isotopic evidence in an arid inland basin | Type | Journal Article | ||
| Year | 2018 | Publication | Hydrological Processes | Abbreviated Journal | |
| Volume | 32 | Issue | 20 | Pages | 3108-3127 |
| Keywords | deuterium excess, groundwater salinization, Northwest China, Manas River basin, stable isotopes | ||||
| Abstract | Abstract In the Manas River basin (MRB), groundwater salinization has become a major concern, impeding groundwater use considerably. Isotopic and hydrogeochemical characteristics of 73 groundwater and 11 surface water samples from the basin were analysed to determine the salinization process and potential sources of salinity. Groundwater salinity ranged from 0.2 to 11.91 g/L, and high salinities were generally located in the discharge area, arable land irrigated by groundwater, and depression cone area. The quantitative contributions of the evaporation effect were calculated, and the various groundwater contributions of transpiration, mineral dissolution, and agricultural irrigation were identified using hydrogeochemical diagrams and δD and δ18O compositions of the groundwater and surface water samples. The average evaporation contribution ratios to salinity were 5.87% and 32.7% in groundwater and surface water, respectively. From the piedmont plain to the desert plain, the average groundwater loss by evaporation increased from 7% to 29%. However, the increases in salinity by evaporation were small according to the deuterium excess signals. Mineral dissolution, transpiration, and agricultural irrigation activities were the major causes of groundwater salinization. Isotopic information revealed that river leakage quickly infiltrated into aquifers in the piedmont area with weak evaporation effects. The recharge water interacted with the sediments and dissolved minerals and subsequently increased the salinity along the flow path. In the irrigation land, shallow groundwater salinity and Cl− concentrations increased but not δ18O, suggesting that both the leaching of soil salts due to irrigation and transpiration effect dominated in controlling the hydrogeochemistry. Depleted δ18O and high Cl− concentrations in the middle and deep groundwater revealed the combined effects of mixing with paleo-water and mineral dissolution with a long residence time. These results could contribute to the management of groundwater sources and future utilization programs in the MRB and similar areas. | ||||
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| Notes | Approved | no | |||
| Call Number | THL @ christoph.kuells @ doi:10.1002/hyp.13243 | Serial | 178 | ||
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| Author | Qi, H.; Ma, C.; He, Z.; Hu, X.; Gao, L. | ||||
| Title |
Lithium and its isotopes as tracers of groundwater salinization: A study in the southern coastal plain of Laizhou Bay, China | Type | Journal Article | ||
| Year | 2019 | Publication | The Science of the Total Environment | Abbreviated Journal | Sci Total Environ |
| Volume | 650 | Issue | Pt 1 | Pages | 878-890 |
| Keywords | Brine and seawater intrusion; Groundwater salinization; Hydrochemistry; Lithium isotope; Southern coastal plain of Laizhou Bay | ||||
| Abstract | In the southern coastal plain of Laizhou Bay, due to intensive exploitation of groundwater since the early 1970s, the shallow aquifer has been severely influenced by saltwater intrusion, which causes the extraction to shift from shallow to deeper aquifer changing the hydrogeological condition greatly. This study was conducted to investigate the groundwater salinization using hydrochemistry and H, O and Li isotope data. Dissolved Li shows a linear correlation with Cl and Br in seawater, brine and saline groundwater indicating the marine Li source, whereas the enrichment of Li in surface water, brackish and fresh groundwater is impacted by dissolution of silicate minerals. The analyses of hydrochemistry and isotopes (H, O and Li) indicate that brine originated from seawater evaporation, followed by mixing processes and some water-rock interactions; shallow saline groundwater originated from brine diluted with seawater and fresh groundwater; deep saline groundwater originated from seawater intrusion. The negative correlation of δ(7)Li and Li/Na in surface water, brackish and fresh groundwater is contrary to the general conclusion, indicating the slow weathering of silicate minerals and hydraulic interaction between surface water and shallow groundwater in this area. The analyses of hydrochemistry and isotopes (Li, H and O) can well identify the salinity sources and isotope fractionation in groundwater flow and mixing, especially groundwater with high TDS. As both mixing with saltwater and isotope fractionation can explain the combination of high δ(7)Li and low TDS in brackish groundwater, isotope fractionation may limit their use in recognizing salinity sources of groundwater with low TDS. | ||||
| Address | School of Environmental Studies, China University of Geosciences, Wuhan 430074, China | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0048-9697 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:30308862 | Approved | no | ||
| Call Number | THL @ christoph.kuells @ | Serial | 184 | ||
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| Author | Siarkos, I.; Latinopoulos, P. | ||||
| Title |
Modeling seawater intrusion in overexploited aquifers in the absence of sufficient data: application to the aquifer of Nea Moudania, northern Greece | Type | Journal Article | ||
| Year | 2016 | Publication | Hydrogeology Journal | Abbreviated Journal | Hydrogeology J. |
| Volume | 24 | Issue | Pages | 2123–2141 | |
| Keywords | Groundwater flow, Seawater intrusion, Numerical modeling, Greece, Sensitivity analysis | ||||
| Abstract | In many coastal areas, overexploitation of groundwater resources has led both to the quantitative degradation of local aquifers and the deterioration of groundwater quality due to seawater intrusion. To investigate the behavior of coastal aquifers under these conditions, numerical modeling is usually implemented; however, the proper implementation of numerical models requires a large amount of data, which are often not available due to the time-consuming and costly process of obtaining them. In the present study, the investigation of the behavior of coastal aquifers under the lack of adequate data is attempted by developing a methodological framework consisting of a series of numerical simulations: a steady-state, a false-transient and a transient simulation. The sequence and the connection between these simulations constitute the backbone of the whole procedure aimed at adjusting the various model parameters, as well as obtaining the initial conditions for the transient simulation. The validity of the proposed methodology is tested through evaluation of the model calibration procedure and the estimation of the simulation errors (mean error, mean absolute error, root mean square error, mean relative error) using the case of Nea Moudania basin, northern Greece. Furthermore, a sensitivity analysis is performed in order to minimize the error estimates and thus to maximize the reliability of the models. The results of the whole procedure affirm the proper implementation of the developed methodology under specific conditions and assumptions due to the lack of sufficient data, while they give a clear picture of the aquifer’s quantitative and qualitative status. |
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| Address | Ilias Siarkos: isiarkos@civil.auth.gr; Pericles Latinopoulos latin@civil.auth.gr | ||||
| Corporate Author | School of Civil Engineering, Aristotle University of Thessaloniki, GR54124 Thessaloniki, Greece | Thesis | |||
| Publisher | IAH | Place of Publication | Editor | Springer | |
| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1431-2174 | ISBN | Medium | ||
| Area | Hydrogeology; groundwater modelling, sea water intrusion | Expedition | Conference | ||
| Notes | Approved | yes | |||
| Call Number | MGRE @ redha.menani @ | Serial | 52 | ||
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