Megacity pumping and preferential flow threaten groundwater quality.
Megacity pumping and preferential flow threaten groundwater quality.
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DOI：
10.1038/ncomms12833
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发表时间：
2016-09-27
影响因子：
16.6
通讯作者：
Michael, Holly A.
中科院分区：
文献类型：
--
作者：
Khan, Mahfuzur R.;Koneshloo, Mohammad;Knappett, Peter S. K.;Ahmed, Kazi M.;Bostick, Benjamin C.;Mailloux, Brian J.;Mozumder, Rajib H.;Zahid, Anwar;Harvey, Charles F.;van Geen, Alexander;Michael, Holly A.
世界上许多大城市依赖地质复杂的含水层中的地下水，这些含水层被过度开采并受到污染威胁。在这里，我们以孟加拉国达卡为例，说明含水层异质性与地下水开采之间的相互作用如何危害区域地下水资源。达卡抽取地下水已造成大规模水位下降，并延伸至外围地区，那里的浅层地下水普遍受到砷污染，并有可能向下迁移。我们利用地下水模型评估深层低砷地下水的脆弱性，其中地下水模型结合了含水层异质性的地质统计模拟。模拟显示，通过典型的河流三角洲含水层地层的优先流可能会在十年内污染深层（>150米）地下水，比根据相同数据校准的均质模型预测的速度快了近一个世纪。最关键的快速流动路径无法通过简化模型来预测或通过标准测量来识别。这种超出城市范围的复杂脆弱性可能成为全球含水层特大城市地下水供应的限制因素。 大城市依赖含水层的地下水，这些地下水可能被过度开采并面临污染的风险。汗等人。对孟加拉国达卡供水的复杂含水层进行了评估，结果表明，大量抽取地下水可能会导致未来城市外深层含水层出现不可预测的砷污染。
Many of the world's megacities depend on groundwater from geologically complex aquifers that are over-exploited and threatened by contamination. Here, using the example of Dhaka, Bangladesh, we illustrate how interactions between aquifer heterogeneity and groundwater exploitation jeopardize groundwater resources regionally. Groundwater pumping in Dhaka has caused large-scale drawdown that extends into outlying areas where arsenic-contaminated shallow groundwater is pervasive and has potential to migrate downward. We evaluate the vulnerability of deep, low-arsenic groundwater with groundwater models that incorporate geostatistical simulations of aquifer heterogeneity. Simulations show that preferential flow through stratigraphy typical of fluvio-deltaic aquifers could contaminate deep (>150 m) groundwater within a decade, nearly a century faster than predicted through homogeneous models calibrated to the same data. The most critical fast flowpaths cannot be predicted by simplified models or identified by standard measurements. Such complex vulnerability beyond city limits could become a limiting factor for megacity groundwater supplies in aquifers worldwide. Megacities rely on groundwater from aquifers that may be over-exploited and be at risk of contamination. Khan et al. evaluate the complex aquifers supplying Dhaka, Bangladesh and show that extensive groundwater pumping could lead to unpredictable future arsenic contamination in deep aquifers outside the city.
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影响因子：
18.3
作者：
Burgess, W. G.;Hoque, M. A.;Ahmed, K. M.
通讯作者：
Ahmed, K. M.
影响因子：
3.7
作者：
Allen, Adriana;Davila, Julio D.;Hofmann, Pascale
通讯作者：
Hofmann, Pascale
影响因子：
5.4
作者：
FOGG, GE
通讯作者：
FOGG, GE
DOI：
10.1007/bf01031292
发表时间：
1983-01-01
期刊：
JOURNAL OF THE INTERNATIONAL ASSOCIATION FOR MATHEMATICAL GEOLOGY
影响因子：
--
作者：
JOURNEL, AG
通讯作者：
JOURNEL, AG
影响因子：
5.4
作者：
Aziz, Z.;van Geen, A.;Ahmed, K. M.
通讯作者：
Ahmed, K. M.