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| Author | Han, D.; Post, V.E.A.; Song, X. | ||||
| Title | Groundwater salinization processes and reversibility of seawater intrusion in coastal carbonate aquifers | Type | Journal Article | ||
| Year | 2015 | Publication | Journal of Hydrology | Abbreviated Journal | |
| Volume | 531 | Issue | Pages | 1067-1080 | |
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| Abstract | Seawater intrusion (SWI) has led to salinization of fresh groundwater reserves in coastal areas worldwide and has forced the closure of water supply wells. There is a paucity of well-documented studies that report on the reversal of SWI after the closure of a well field. This study presents data from the coastal carbonate aquifer in northeast China, where large-scale extraction has ceased since 2001 after salinization of the main well field. The physical flow and concomitant hydrogeochemical processes were investigated by analyzing water level and geochemical data, including major ion chemistry and stable water isotope data. Seasonal water table and salinity fluctuations, as well as changes of δ2H–δ18O values of groundwater between the wet and dry season, suggest local meteoric recharge with a pronounced seasonal regime. Historical monitoring testifies of the reversibility of SWI in the carbonate aquifer, as evidenced by a decrease of the Cl− concentrations in groundwater following restrictions on groundwater abstraction. This is attributed to the rapid flushing in this system where flow occurs preferentially along karst conduits, fractures and fault zones. The partially positive correlation between δ18O values and TDS concentrations of groundwater, as well as high NO3− concentrations (\textgreater39mg/L), suggest that irrigation return flow is a significant recharge component. Therefore, the present-day elevated salinities are more likely due to agricultural activities rather than SWI. Nevertheless, seawater mixing with fresh groundwater cannot be ruled out in particular where formerly intruded seawater may still reside in immobile zones of the carbonate aquifer. The massive expansion of fish farming in seawater ponds in the coastal zone poses a new risk of salinization. Cation exchange, carbonate dissolution, and fertilizer application are the dominant processes further modifying the groundwater composition, which is investigated quantitatively using hydrogeochemical models. | ||||
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| Publisher | Elsevier | 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 @ Han2015 | Serial  |
24 | ||
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| Author | Hanshaw, B.B.; Back, W. | ||||
| Title | Deciphering hydrological systems by means of geochemical processes | Type | Journal Article | ||
| Year | 1985 | Publication | Hydrological Sciences Journal | Abbreviated Journal | |
| Volume | 30 | Issue | 2 | Pages | 257-271 |
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| Abstract | The distribution of permeability and chemical character of groundwater in carbonate aquifers is significantly influenced by the many diagenetic processes and reactions that occur in the early development of these rocks. Many of these diagenetic processes occur in the transition zone formed as the carbonate sediments emerge from the marine environment and become fresh-water aquifers. Analyses of trace elements and isotopes indicate that calcite cements and dolomites are formed in this groundwater mixing zone. Reverse reactions such as mineral dissolution and dedolomitization occur in carbonate aquifer systems. The geochemical reactivity of the fresh-water/salt-water mixing zone results from the nonlinearity of geochemical parameters as a function of ionic strength and causes extensive dissolution in coastal carbonate rocks. Interpretation of geochemical reactions and isotopic composition of groundwater provides a method to determine hydrological parameters such as porosity, hydraulic conductivity, and groundwater flow rates. This geochemical method is largely independent of the more conventional approach of determining these parameters by an evaluation of physical properties of aquifer systems. |
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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 | 0262-6667 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | THL @ christoph.kuells @ Hanshaw1985 | Serial |
25 | ||
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| Author | Hanshaw, B.B.; Back, W. | ||||
| Title | Major geochemical processes in the evolution of carbonate—Aquifer systems | Type | Journal Article | ||
| Year | 1979 | Publication | Journal of Hydrology | Abbreviated Journal | |
| Volume | 43 | Issue | 1 | Pages | 287-312 |
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| Abstract | As a result of recent advances by carbonate petrologists and geochemists, hydrologists are provided with new insights into the origin and explanation of many aquifer characteristics and hydrologic phenomena. Some major advances include the recognition that: (1) most carbonate sediments are of biological origin; (2) they have a strong bimodal size-distribution; and (3) they originate in warm shallow seas. Although near-surface ocean water is oversaturated with respect to calcite, aragonite, dolomite and magnesite, the magnesium-hydration barrier effectively prevents either the organic or inorganic formation of dolomite and magnesite. Therefore, calcareous plants and animals produce only calcite and aragonite in hard parts of their bodies. Most carbonate aquifers that are composed of sand-size material have a high initial porosity; the sand grains that formed these aquifers originated primarily as small shells, broken shell fragments of larger invertebrates, or as chemically precipitated oolites. Carbonate rocks that originated as fine-grained muds were initially composed primarily of aragonite needles precipitated by algae and have extremely low permeability that requires fracturing and dissolution to develop into aquifers. Upon first emergence, most sand beds and reefs are good aquifers; on the other hand, the clay-sized carbonate material initially has high porosity but low permeability, a poor aquifer property. Without early fracture development in response to influences of tectonic activity these calcilutites would not begin to develop into aquifers. As a result of selective dissolution, inversion of the metastable aragonite to calcite, and recrystallization, the porosity is collected into larger void spaces, which may not change the overall porosity, but greatly increases permeability. Another major process which redistributes porosity and permeability in carbonates is dolomitization, which occurs in a variety of environments. These environments include back-reefs, where reflux dolomites may form, highly alkaline, on-shore and continental lakes, and sabkha flats; these dolomites are typically associated with evaporite minerals. However, these processes cannot account for most of the regionally extensive dolomites in the geologic record. A major environment of regional dolomitization is in the mixing zone (zone of dispersion) where profound changes in mineralogy and redistribution of porosity and permeability occur from the time of early emergence and continuing through the time when the rocks are well-developed aquifers. The reactions and processes, in response to mixing waters of differing chemical composition, include dissolution and precipitation of carbonate minerals in addition to dolomitization. An important control on permeability distribution in a mature aquifer system is the solution of dolomite with concomitant precipitation of calcite in response to gypsum dissolution (dedolomitization). Predictive models developed by mass-transfer calculations demonstrate the controlling reactions in aquifer systems through the constraints of mass balance and chemical equilibrium. An understanding of the origin, chemistry, mineralogy and environments of deposition and accumulation of carbonate minerals together with a comprehension of diagenetic processes that convert the sediments to rocks and geochemical, tectonic and hydrologic phenomena that create voids are important to hydrologists. With this knowledge, hydrologists are better able to predict porosity and permeability distribution in order to manage efficiently a carbonate—aquifer system. | ||||
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| 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 @ Hanshaw1979 | Serial |
26 | ||
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| Author | Kafri, U.; Goldman, M.; Lyakhovsky, V.; Scholl, C.; Helwig, S.; Tezkan, B. | ||||
| Title | The configuration of the fresh–saline groundwater interface within the regional Judea Group carbonate aquifer in northern Israel between the Mediterranean and the Dead Sea base levels as delineated by deep geoelectromagnetic soundings | Type | Journal Article | ||
| Year | 2007 | Publication | Journal of Hydrology | Abbreviated Journal | |
| Volume | 344 | Issue | 1 | Pages | 123-134 |
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| Abstract | A combined high resolution short offset transient electromagnetic (SHOTEM) and deep sounding, long offset (LOTEM) survey has been carried out along two traverses between the Mediterranean Sea and the Jordan-Dead Sea Rift (DSR). The DSR is located in the study area some 200–250m below sea level. The measurements detected a deep conductor, the top of which exhibited a regular behavior along the both traverses, declining from the Mediterranean to the DSR base level. The geometry of this geoelectric boundary coincides fairly well with the configuration of a supposed fresh/saline groundwater interface as also obtained by both numerical and physical modeling for the known hydrogeological conditions in the study area. Therefore the detected geoelectric boundary is identified with the interface, supporting the hypothesis of current seawater intrusion into the deep regional aquifers between the Mediterranean and the DSR base levels. The intrusion causes the salination of fresh groundwater within the aquifers as well as the salination of the Sea of Galilee. | ||||
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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 @ Kafri2007 | Serial |
27 | ||
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| Author | Karistineos, N.; Ioakim, C. | ||||
| Title | Palaeoenvironmental and palaeoclimatic evolution of the serres basin (N. Greece) during the miocene | Type | Journal Article | ||
| Year | 1989 | Publication | Palaeogeography, Palaeoclimatology, Palaeoecology | Abbreviated Journal | |
| Volume | 70 | Issue | 1-3 | Pages | 275-285 |
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| Abstract | The palaeoenvironmental and palaeoclimatic evolution of the Serres basin from the end of mid-Miocene to the end of the Miocene is examined. Lignites were deposited over a thick sequence of conglomerates and sands. Fossils found in the lignites indicate a lacustrine environment with tropical-subtropical climatic conditions. The climate became progressively drier and only small lakes were reserved during the Messinian salinity crisis. Deposition of lake sediments finally ended with the world-wide Pliocene marine transgression. A correlation of the Serres basin with other lacustrine basins in the Aegean area is attempted. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Elsevier | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0031-0182 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | THL @ christoph.kuells @ Karistineos1989 | Serial |
28 | ||
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