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Titel |
Recent trends in groundwater levels in a highly seasonal hydrological system: the Ganges-Brahmaputra-Meghna Delta |
VerfasserIn |
M. Shamsudduha, R. E. Chandler, R. G. Taylor, K. M. Ahmed |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 13, no. 12 ; Nr. 13, no. 12 (2009-12-10), S.2373-2385 |
Datensatznummer |
250012071
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Publikation (Nr.) |
copernicus.org/hess-13-2373-2009.pdf |
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Zusammenfassung |
Groundwater levels in shallow aquifers underlying Asian mega-deltas are
characterized by strong seasonal variations associated with monsoon
rainfall. To resolve trend and seasonal components in weekly groundwater
levels in the Ganges-Brahmaputra-Meghna (GBM) Delta, we apply a
nonparametric seasonal-trend decomposition procedure (STL) to observations
compiled from 1985–2005 in Bangladesh. Seasonality dominates observed
variance in groundwater levels but declining groundwater levels (>1 m/yr)
are detected in urban and peri-urban areas around Dhaka as well as in
north-central, northwestern, and southwestern parts of the country (0.1–0.5 m/yr)
where intensive abstraction of groundwater is conducted for
dry-season rice cultivation. Rising groundwater levels (0.5–2.5 cm/yr)
are observed in the estuarine and southern coastal regions. This novel
application of the STL procedure reveals, for the first time, the
unsustainability of irrigation supplied by shallow aquifers in some areas
(e.g., High Barind Tract) of the GBM Delta and the hydrological impact of
potential seawater intrusion of coastal aquifers associated with sea-level
rise. Our findings provide important insight into the hydrological impacts
of groundwater-fed irrigation and sea-level rise in other Asian mega-deltas
where monitoring data are limited. |
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