Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin
Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin
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DOI：
10.1073/pnas.0710477105
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发表时间：
2008-06-24
影响因子：
11.1
通讯作者：
Voss, Clifford I.
中科院分区：
文献类型：
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作者：
Michael, Holly A.;Voss, Clifford I.
孟加拉国和印度的孟加拉盆地地区有数千万人饮用含有不安全浓度砷的地下水。这种高砷地下水产自浅层（150 m），地下水砷浓度几乎一致较低，需要更多的威尔斯井，但是，以前没有评估过深层砷安全地下水的可持续性。更深的抽水可能导致溶解的砷向下迁移，永久性地破坏深层资源。在这里，它表明，通过定量，大规模的水文地质分析和模拟整个流域，较深的含水层系统的一部分，可以提供一个可持续的砷安全水源，如果它的利用仅限于国内供应。模拟提供了两种解释，这一结果：深国内抽水只有轻微扰动深层地下水流系统，和大量的浅抽水灌溉形成了一个水力屏障，保护较深的资源从浅砷源。进一步的分析表明，这种简单的管理方法可以在1,000年的时间内为90%以上的砷污染地区提供砷安全的饮用水。这一见解可能有助于水资源管理者缓解世界上最大的地下水污染问题之一。
Tens of millions of people in the Bengal Basin region of Bangladesh and India drink groundwater containing unsafe concentrations of arsenic. This high-arsenic groundwater is produced from shallow (150 m where groundwater arsenic concentrations are nearly uniformly low, and many more wells are needed, however, the sustainability of deep, arsenic-safe groundwater has not been previously assessed. Deeper pumping could induce downward migration of dissolved arsenic, permanently destroying the deep resource. Here, it is shown, through quantitative, large-scale hydrogeologic analysis and simulation of the entire basin, that the deeper part of the aquifer system may provide a sustainable source of arsenic-safe water if its utilization is limited to domestic supply. Simulations provide two explanations for this result: deep domestic pumping only slightly perturbs the deep groundwater flow system, and substantial shallow pumping for irrigation forms a hydraulic barrier that protects deeper resources from shallow arsenic sources. Additional analysis indicates that this simple management approach could provide arsenic-safe drinking water to >90% of the arsenic-impacted region over a 1,000-year timescale. This insight may assist water-resources managers in alleviating one of the world's largest groundwater contamination problems.