区域地下水污染综合评价研究现状与建议

区域地下水污染综合评价研究是一项总结区域地下水水质特征、评估地下水水质和污染状况、分析其驱动机制、研判其演化趋势的重要基础性工作,也是地下水污染防控以及水质改善的重要依据。受水文地质领域一些传统概念、观念以及技术方法的限制,在水质综合评价、污染评价、天然劣质水与污染的区分、人类活动影响等方面存在诸多问题和挑战,认知的科学性和可靠性不断受到质疑,给政府管理部门的应用和决策带来困惑。本研究通过梳理分析近年来区域地下水污染综合评价的研究现状,回顾总结了在水质综合评价、背景值、污染评价、劣质水和劣变水评估以及人类活动识别等方面存在的问题,提出了几点认识和建议:(1)“指标分类评价-组合表达”的水质及污染综合评价思路,可为解决现阶段水质及污染综合评估容易造成歧义和误导的问题提供新的方向;(2)视背景值的建立不仅能够解决传统概念背景值无法获取的问题,还能有效进行污染判定、劣质水和劣变水评估以及人类活动识别,是一项亟待全面开展的基础性工作;(3)劣质水和劣变水概念及评价思路的提出,对区分天然劣质水和污染水具有借鉴意义,在科学回答这两类水对我国地下水水质的影响、帮助决策者理解水质不安全成因等方面有重要意义,但是方法学方面需要进一步探讨;(4)对人类活动影响的识别和量化,进一步推动了对输入型污染、诱导型水质恶化以及水化学场变化所引起的各种水质问题的认识,进而对判断水质演化趋势、污染防控、分类解决水质问题具有重要的意义。

Comprehensive evaluation of regional groundwater pollution:Research status and suggestions

A comprehensive evaluation of regional groundwater pollution is essential for understanding the regional groundwater quality characteristics, pollution status and mechanism, and groundwater quality evolution. Such evaluation also serves as an important basis for groundwater pollution prevention and control and water quality improvement. However, due to inherent limitations of certain conventional concepts, opinions and research practices in the field of hydrogeology, there are many problems and challenges associated with groundwater quality and pollution evaluation, such as the lacks of clear distinction between natural poor quality water and polluted water and impact assessment of human activities. Therefore, the reliability of the evaluation results is often questioned, which causes confusion among government agencies over pollution control application and decision making. To improve this situation, this study sought to assess the current status of comprehensive evaluation of regional groundwater pollution based on the evaluation results of recent years, review the problems associated with the groundwater quality evaluation, background value, pollution evaluation, and distinction between poor water quality and water quality degradation, identify the anthropogenic pollution activities, and ultimately make some suggestions. The resulting suggestions include: (1) Establish an evaluation framework with the “indicator classification evaluation-combination expression” approach to minimize ambiguity and misleadings in the evaluation results. (2) Establish apparent background value to facilitate the assessment of pollution status, differentiation between poor water quality and water quality deterioration, and identification of impactful anthropogenic activities. (3) Clarify the distinction between poor quality water and quality degraded water in order to effectively distinguish between natural poor quality water and polluted water, elucidate the impact of these water types on the groundwater quality, and help decision-makers understand the causes of unsafe water. (4) Identify and quantify anthropogenic pollution activities to help understand water pollution caused by imported pollution, induced water quality deterioration and change of water hydrochemical property, and highlight the trends of groundwater quality evolution to develop better pollution prevention and control methods.