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| Titel |
Inter-relationship between shallow and deep aquifers under the influence of
deep groundwater exploitation in the North China Plain |
| VerfasserIn |
Dongmei Han, Guoliang Cao, Andrew J. Love |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144410
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| Publikation (Nr.) |
 EGU/EGU2017-8230.pdf |
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| Zusammenfassung |
| In the North China Plain (NCP), the interaction between shallow and deep
groundwater flow systems enhanced by groundwater extraction has been
investigated using multi-isotopic and chemical tracers for understanding the
mechanism of salt water transport, which has long been one of the major
regional environmental hydrogeological problems in NCP. Information about
the problem will be determined using multiple lines of evidence, including
field surveys of drilling and water sampling, as well as laboratory
experiments and physical and numerical simulations. A conceptual model of
groundwater flow system along WE cross-section from piedmont area to coastal
region (Shijiazhuang-Hengshui-Cangzhou) has been developed and verified by
geochemical modeling. A combined hydrogeochemical and isotopic investigation
using ion relationships such as Cl/Br ratios, and environment isotopes
($\delta ^{18}$O, $\delta ^{2}$H, $\delta ^{34}$S$_{SO4}-\delta
^{18}$O$_{SO4}$, $\delta ^{15}$N$_{NO$_3$}-\delta ^{18}$O$_{NO$_3$}$,
$\delta ^{13}$C and $^{87}$Sr/$^{86}$Sr) was reviewed and carried for
determining the sources of aquifer recharge, the origin of solutes and the
mixing processes in groundwater flow system under the anthropogenic pumping
and pollution. Results indicate that hydrochemistry of groundwater is
characterized by mixing between end-members coming directly from Piedmont
recharge areas, saline groundwater formed during geohistorical transgression
in the shallow aquifers of central plain, and to groundwater circulating in
a deeply buried Quaternary sediments. We also reviewed the groundwater age
(tritium contents, $^{14}$C ages, $^{3}$H-$^{3}$He ages, basin-scale flow
modeling ages of groundwater) to recognize the local distributed recharge in
this strongly exploited aquifer system. Finally, combined with the 1-D Cl
transport modeling for the pore water of clay-rich aquitard, we reveal that
salt transport in the aquitard is primarily controlled by vertical diffusion
on million years' time scale, and the observed the salinized groundwater in
deep aquifer may be caused by passing through ``windows'' or preferential
flow path, rather than vertical flow through the aquitard. |
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