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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 | ||
Series Editor | Series Title | Abbreviated Series Title | |||
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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Author | Zhao, Q.; Su, X.; Kang, B.; Zhang, Y.; Wu, X.; Liu, M. | ||||
Title | A hydrogeochemistry and multi-isotope (Sr, O, H, and C) study of groundwater salinity origin and hydrogeochemcial processes in the shallow confined aquifer of northern Yangtze River downstream coastal plain, China | Type | Journal Article | ||
Year | 2017 | Publication | Applied Geochemistry | Abbreviated Journal | |
Volume | 86 | Issue ![]() |
Pages | 49-58 | |
Keywords | Coastal confined groundwater, Salinity, Hydrogeochemcial processes, Multiple environmental tracers | ||||
Abstract | Economically developed coastal areas have a high water demand, and their groundwater resources can be threatened by salinization. Many methods and tracers have been used to discriminate the source of salinization because a single method does not yield reliable results. In this paper, the shallow confined coastal plain aquifer, north of the downstream Yangtze River in China, is used as a case study to investigate the origin of the salinity and the relevant geochemical processes for this aquifer. Multiple environmental tracers of major ions, minor ions (Br−, I−), and isotopes (18O, 2H, 13C, 87Sr, 3H, 14C) were used so as to provide reliable conclusions. The TDS distribution of the aquifer has an increasing trend, from below 500 mg/L in the inland areas to more than 20,000 mg/L around the southeast coastline. The water chemical type evolves from HCO3-Ca to Cl-Na as the TDS increases. The results suggest that the groundwater salinity is influenced by seawater intrusion. The seawater proportions in the groundwater samples range from 0.07% to 94.41% and show the same spatial distribution pattern as TDS. The 3H and 14C values show that the highest salinity was mainly caused by a seawater transgression around 6000a B.P. The aquifer is also affected by other hydrogeochemical processes: base exchange has enriched Ca2+ and depleted K+ and Na+, sulfate reduction has reduced the concentration of SO42− and enriched HCO3−, and iodine-rich organic matter decomposition has enriched the concentration of I−. The iodine enrichment also suggests paleo-seawater intrusion. In addition, the precipitation of carbonate minerals has decreased the concentration of Ca2+, Mg2+, and HCO3−, albeit to a limited extent. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0883-2927 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | THL @ christoph.kuells @ Zhao201749 | Serial | 182 | ||
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Author | Cary, L.; Petelet-Giraud, E.; Bertrand, G.; Kloppmann, W.; Aquilina, L.; Martins, V.; Hirata, R.; Montenegro, S.M.G.L.; Pauwels, H.; Chatton, E.; Franzen, Melissa; Aurouet, A.; Lasseur, E.; Picot-Colbeaux, G.; Guerrot, C.; Fléhoc, C.; Labasque, T.; Santos, Jeane Glaucia; Paiva, Anderson L.R.; Braibant, G.; Pierre, D. | ||||
Title | Origins and processes of groundwater salinization in the urban coastal aquifers of Recife (Pernambuco, Brazil): a multi-isotope approach | Type | Journal Article | ||
Year | 2015 | Publication | Science of the Total Environment | Abbreviated Journal | |
Volume | 530-531 | Issue ![]() |
Pages | 411-429 | |
Keywords | Salinization origins; Salinization processes; Groundwater; Coastal aquifer; Strontium isotopes; Boron isotopes; Recife; Brazil | ||||
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Publisher | Elsevier | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
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ISSN | ISBN | Medium | |||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | THL @ christoph.kuells @ cary:hal-01161949 | Serial | 85 | ||
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Author | Han, D.M.; Song, X.F.; Currell, M.J.; Yang, J.L.; Xiao, G.Q. | ||||
Title | Chemical and isotopic constraints on evolution of groundwater salinization in the coastal plain aquifer of Laizhou Bay, China | Type | Journal Article | ||
Year | 2014 | Publication | Journal of Hydrology | Abbreviated Journal | |
Volume | 508 | Issue ![]() |
Pages | 12-27 | |
Keywords | Laizhou Bay, Coastal aquifers, Groundwater hydrochemistry, Stable isotopes, Saltwater intrusion | ||||
Abstract | Summary A hydrochemical-isotopic investigation of the Laizhou Bay Quaternary aquifer in north China provides new insights into the hydrodynamic and geochemical relationships between freshwater, seawater and brine at different depths in coastal sediments. Saltwater intrusion mainly occurs due to two cones of depression caused by concentrated exploitation of fresh groundwater in the south, and brine water for salt production in the north. Groundwater is characterized by hydrochemical zonation of water types (ranging from Ca–HCO3 to Na–Cl) from south to north, controlled by migration and mixing of saline water bodies with the regional groundwater. The strong adherence of the majority of ion/Cl ratios to mixing lines between freshwater and saline water end-members (brine or seawater) indicates the importance of mixing under natural and/or anthropogenic influences. Examination of the groundwater stable isotope δ18O and δ2H values (between −9.5‰ and −3.0‰ and −75‰ and −40‰, respectively) and chloride contents (∼2 to 1000meq/L) of the groundwater indicate that the saline end-member is brine rather than seawater, and most groundwater samples plot on mixing trajectories between fresh groundwater (δ18O of between −6.0‰ and −9.0‰; Cl<5meq/L) and sampled brines (δ18O of approximately −3.0‰ and Cl>1000meq/L). Locally elevated Na/Cl ratios likely result from ion exchange in areas of long-term freshening. The brines, with radiocarbon activities of ∼30 to 60 pMC likely formed during the Holocene as a result of the sequence of transgression-regression and evaporation; while deep, fresh groundwater with depleted stable isotopic values (δ18O=−9.7‰ and δ2H=−71‰) and low radiocarbon activity (<20 pMC) was probably recharged during a cooler period in the late Pleistocene, as is common throughout northern China. An increase in the salinity and tritium concentration in some shallow groundwater sampled in the 1990s and re-sampled here indicates that intensive brine extraction has locally resulted in rapid mixing of young, fresh groundwater and saline brine. The δ18O and δ2H values of brines (∼−3.0‰ and −35‰) are much lower than that of modern seawater, which could be explained by 1) mixing of original (δ18O enriched) brine that was more saline than presently observed, with fresh groundwater recharged by precipitation and/or 2) dilution of the palaeo-seawater with continental runoff prior to and/or during brine formation. The first mechanism is supported by relatively high Br/Cl molar ratios (1.7×10−3–2.5×10−3) in brine water compared with ∼1.5×10−3 in seawater, which could indicate that the brines originally reached halite saturation and were subsequently diluted with fresher groundwater over the long-term. Decreasing 14C activities with increasing sampling depth and increasing proximity to the coastline indicate that the south coastal aquifer in Laizhou Bay is dominated by regional lateral flow, on millennial timescales. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-1694 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | THL @ christoph.kuells @ Han201412 | Serial | 174 | ||
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Author | Gopinath, S.; Srinivasamoorthy, K.; Saravanan, K.; Prakash, R. | ||||
Title | Tracing groundwater salinization using geochemical and isotopic signature in Southeastern coastal Tamilnadu, India | Type | Journal Article | ||
Year | 2019 | Publication | Chemosphere | Abbreviated Journal | |
Volume | 236 | Issue ![]() |
Pages | 124305 | |
Keywords | Coastal groundwater, Hydrochemistry, Isotopes, Thermodynamics, Statistical analysis | ||||
Abstract | Attempt has been made to discriminate groundwater salinity causes along the east coast of India. A total of 122 groundwater samples (61/season) were collected for two diverse seasons (Pre Monsoon and Post Monsoon) and analyzed for physical and chemical components along with stable isotopes. The Piper diagram proposes samples along the coast predisposed by saltwater incursion. Ionic ratio plots recommend groundwater discriminatory by changing geochemical signatures. The statistical correlation suggests impact of saltwater incursion, anthropogenic and rock water interaction as sources for dissolved constituents in groundwater. The thermodynamic stability plot suggests higher silicate dissolution, weathering and ion exchange prompting water chemistry nevertheless of seasons. The δ 18O and δ 2H increases towards the sea suggesting enrichment attributed to the sea water influence and rainfall influences along the southwestern parts of the study area. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0045-6535 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | THL @ christoph.kuells @ Gopinath2019124305 | Serial | 176 | ||
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