Palaeosol control on groundwater flow and pollutant distribution: the example of arsenic.
Palaeosol control on groundwater flow and pollutant distribution: the example of arsenic.
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DOI：
10.1021/es1032376
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发表时间：
2011-02
影响因子：
11.4
通讯作者：
J. McArthur;B. Nath;D. M. Banerjee;R. Purohit;N. Grassineau
中科院分区：
文献类型：
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作者：
J. McArthur;B. Nath;D. M. Banerjee;R. Purohit;N. Grassineau
饮用受砷污染的地下水对人类健康有严重的不利影响，特别是在东南亚部分地区，地下水主要来自河流/三角洲含水层。在这样的含水层中的As-污染的横向分布是不均匀的。异质性的原因尚不清楚。因此，作为污染的位置和严重程度是难以预测的，尽管这种预测的重要性，以保护消费者的健康，含水层的补救措施，含水层的发展。为了解释这种不均匀性，我们使用西孟加拉102 km（2）的659口威尔斯井绘制了地下水中的As污染图，并记录了43个钻孔，以揭示As污染的分布受地下沉积学的控制。在47 km（2）的连续古河间，我们发现浅层含水层（50 μg/L）。古土壤的作用，特别是LGMP，一直被忽视的控制地下水流和污染物的运动在世界各地的三角洲和沿海含水层。在这种环境中的污染物渗透模型必须包括这样的认识，即在存在LGMP（或其他古土壤）的地方，补给在古河道区域向下移动，这些区域被古河间区域隔开，在这些区域，不能向下层含水层垂直补给，而在LGMP及其覆盖的任何含水层上方发生水平流动。
The consumption of groundwater polluted by arsenic (As) has a severe and adverse effect on human health, particularly where, as happens in parts of SE Asia, groundwater is supplied largely from fluvial/deltaic aquifers. The lateral distribution of the As-pollution in such aquifers is heterogeneous. The cause of the heterogeneity is obscure. The location and severity of the As-pollution is therefore difficult to predict, despite the importance of such predictions to the protection of consumer health, aquifer remediation, and aquifer development. To explain the heterogeneity, we mapped As-pollution in groundwater using 659 wells across 102 km(2) of West Bengal, and logged 43 boreholes, to reveal that the distribution of As-pollution is governed by subsurface sedimentology. Across 47 km(2) of contiguous palaeo-interfluve, we found that the shallow aquifer (50 μg/L). The role of palaeosols and, in particular, the LGMP, has been overlooked as a control on groundwater flow and pollutant movement in deltaic and coastal aquifers worldwide. Models of pollutant infiltration in such environments must include the appreciation that, where the LGMP (or other palaeosols) are present, recharge moves downward in palaeo-channel regions that are separated by palaeo-interfluvial regions where vertical recharge to underlying aquifers cannot occur and where horizontal flow occurs above the LGMP and any aquifer it caps.