Recent trends in groundwater levels in a highly seasonal hydrological system: the Ganges-Brahmaputra-Meghna Delta.
HYDROL EARTH SYST SC
2373 - 2385.
Available under License : See the attached licence file.
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.
|Title:||Recent trends in groundwater levels in a highly seasonal hydrological system: the Ganges-Brahmaputra-Meghna Delta|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||© Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License.|
|Keywords:||ARSENIC-CONTAMINATED AQUIFER, LOCALLY WEIGHTED REGRESSION, BENGAL BASIN, WATER-QUALITY, RED-RIVER, BANGLADESH, MOBILIZATION, DYNAMICS, VIETNAM, HANOI|
|UCL classification:||UCL > School of Arts and Social Sciences > Faculty of Social and Historical Sciences > Geography
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Institute for Risk and Disaster Reduction
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Statistical Science
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