Huan Huan, Hu Litang, Yang Yu, Jia Yongfeng, Lian Xinying, Ma Xiongfei, Jiang Yonghai, Xi Beidou
Technical Centre for Soil, Agricultural and Rural Ecology and Environment, Ministry of Ecology and Environment of the People's Republic of China, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
College of Water Sciences, Beijing Normal University, Beijing 100875, China.
Environ Int. 2020 Apr;137:105532. doi: 10.1016/j.envint.2020.105532. Epub 2020 Feb 18.
Groundwater pollution risk assessment in the groundwater source field (GSF) is crucial to ensure groundwater quality safety. A systematic method of assessing groundwater pollution in the GSF was established by combining the numerical models of groundwater flow and solute transport in the vadose zone and aquifer. It is featured by revealing the paramount fate of contaminant from the surface to receptor "well (wells)" via the pathway of vadose zone and aquifers. The method was verified in the phreatic and semi-confined aquifers of a vital GSF, Beijing-Tianjin-Hebei region (BTHR) in China. Nitrate was selected as the model pollutant. The results indicated that the groundwater pollution risk of the phreatic aquifer was dominated by the mediate level (45.27%), and that the second semi-confined aquifer was mainly ranked as relatively low (30.29%) and mediate (38.17%) levels. The groundwater pollution risk maps of the two aquifers were similar. The high and relatively high risk areas were affected by the high intensities of groundwater pollution sources (GPSIs) or short distances from the pollution sources to the pumping well. The low and relatively low risk areas were controlled by low GPSIs and adequate attenuation and denitrification of nitrate in the aquifer. The groundwater pollution risk in the semi-confined aquifer was lower than that in the phreatic aquifer. The groundwater pollution risk mapping provides a valuable scientific reference for the groundwater pollution prevention and control with the focus on the "pollution source" and "groundwater source field". The proposed method can be further applied to the protections of the GSFs in the BTHR.
地下水源地的地下水污染风险评估对于确保地下水质量安全至关重要。通过结合包气带和含水层中地下水流与溶质运移的数值模型，建立了一种系统的地下水源地地下水污染评估方法。其特点是揭示污染物从地表通过包气带和含水层路径到受体“井（多口井）”的首要归宿。该方法在中国京津冀地区一个重要地下水源地的潜水含水层和半承压含水层中得到验证。选择硝酸盐作为模型污染物。结果表明，潜水含水层的地下水污染风险以中等水平为主（45.27%），而第二半承压含水层主要为相对较低水平（30.29%）和中等水平（38.17%）。两个含水层的地下水污染风险图相似。高风险和相对高风险区域受高强度地下水污染源影响或距污染源到抽水井的距离较短。低风险和相对低风险区域受低强度地下水污染源以及含水层中硝酸盐充分衰减和反硝化作用控制。半承压含水层的地下水污染风险低于潜水含水层。地下水污染风险制图为以“污染源”和“地下水源地”为重点的地下水污染防治提供了有价值的科学参考。所提出的方法可进一步应用于京津冀地区地下水源地的保护。
