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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 (up) 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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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 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 (up) 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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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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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 (up) 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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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1866-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Sarker2018 Serial 194
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Author El Mandour, A.; El Yaouti, F.; Fakir, Y.; Zarhloule, Y.; Benavente, J.
Title Evolution of groundwater salinity in the unconfined aquifer of Bou-Areg, Northeastern Mediterranean coast, Morocco Type Journal Article
Year 2007 Publication (up) Environmental Geology Abbreviated Journal
Volume 54 Issue 3 Pages 491-503
Keywords Unconfined aquifer, Groundwater salinity, Seawater intrusion, Nitrate pollution, Lagoon, Morocco  Bou-Areg
Abstract The Bou-Areg plain in the Mediterranean coast at the North-eastern of Morocco is characterized by a semiarid climate. The aquifer consists of two sedimentary formations of Plio-quaternary age: the upper formation of fine silts and the lower one of coarse silts with sand and gravels. The aquifer is underlain by marly bedrock of Miocene age that dips toward the coastal lagoon of Bou-Areg. The

hydrodynamic characteristics vary between 10–4 and 10–3 m/s; and transmissivities range between 10–4 and 10–1 m2 /s. The general direction of flow is SW to NE, toward the lagoon. The aquifer is crossed by the river Selouane, which also ends in the lagoon. The groundwater is characterized by a high salinity that can reach 7.5 g/l. The highest values are observed in the upstream and in the downstream sectors of the aquifer. The temporal evolution of the physicochemical parameters depends on the climatic conditions and

piezometric variations. The analysis of the spatio-temporal distribution of the physico-chemical parameters suggests different sources of groundwater salinization: the seawater intrusion, the influence of marly gypsum-bearing terrains, and the influence of anthropogenic products as the agricultural fertilizers, which cause great nitrate concentrations that vary between 80 and 140 mg/l.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0943-0105 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ luqianxue.zhang @ ElMandour2008 Serial 44
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Author Di Lorenzo, T.; Galassi, D.M.P.
Title Agricultural impact on Mediterranean alluvial aquifers: do groundwater communities respond? Type Journal Article
Year 2013 Publication (up) Fundamental and Applied Limnology/Archiv für Hydrobiologie Abbreviated Journal
Volume 182 Issue 4 Pages 271-282
Keywords alluvial aquifers, groundwater, stygobiont, nitrate, overexploitation
Abstract In Mediterranean countries agricultural development heavily depends on groundwater availability due

to arid and semi-arid climate and poor surface-water resources. Agriculture represents one of the most relevant

pressures which generate impacts in alluvial aquifers by means of fertilizers and pesticides usage and groundwater

overexploitation. Until now, very few studies have addressed the ecological response of groundwater fauna to

groundwater contamination and overexploitation due to agricultural practices. We investigated a Mediterranean

alluvial aquifer heavily affected by nitrates contamination and groundwater abstraction stress due to crop irrigation. The aim of this study was to evaluate the sensitivity of groundwater communities to (a) groundwater nitrate

contamination, (b) groundwater abstraction due to irrigation practices, and (c) saltwater intrusion. The present

work suggests that nitrate concentration lower than 150 mg l

–1 is not an immediate threat to groundwater biodiversity in alluvial aquifers. This conclusion must be carefully considered in the light of the total lack of knowledge

of the effects of long-term nitrate pollution on the groundwater biota. Moreover, local extinctions of less tolerant

species, prior to monitoring, cannot be ruled out. Conversely, species abundances in ground water are affected by

groundwater withdrawal, but species richness may be less sensitive. This result is attributable to the disappearance

of saturated microhabitats and to the depletion of fine unconsolidated sediments, reducing the surface available

to bacterial biofilm, which represent the trophic resource for several groundwater invertebrates and where the

main aquifer self-purification processes, such as denitrification, take place. Saltwater intrusion seems not to affect

groundwater species at the values measured in this coastal aquifer.
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Corporate Author Thesis
Publisher E. Schweizerbart'sche Verlagsbuchhandlung Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1863-9135 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ luqianxue.zhang @ DiLorenzo2013 Serial 43
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