基于FEFLOW的大型矿区地下水多源污染风险评价及长效监控机制研究——以某大型铜钼矿区为例

Study of Large-Scale Mining Groundwater Multi-Source Pollution Risk Assessment and Long Term Monitoring Mechanism Based on FEFLOW

随着社会经济的快速增长和人民物质需求的逐步提高,国家对矿产资源的需求显著加剧,然而由矿产开采所引起的环境问题也逐步增多,特别是矿山开采引起的地下水位下降以及配套工程会形成的复杂污染源,严重影响着矿区及周边地下水环境,因此对大型矿区多源污染风险及其监控机制的研究是迫切需要的。本文选取某大型铜钼矿区为研究对象,基于对研究区水文地质条件的剖析,概化为合理的水文地质模型,并采用FEFLOW软件开展数值建模研究,对矿区不同工况下多源污染物的迁移规律进行预测分析。模拟结果显示在矿区无抽水条件下,多源污染物的迁移基本随天然地下水的径流方向迁移与扩散;而在抽水条件下,矿区临近污染源的迁移不仅受到地下水流向的控制,还受控于矿区的抽排水影响,使得临近的污染源的污染物向进行抽排水的矿区迁移与扩散。根据对多源污染物空间迁移规律的掌握,对矿区地下水长效监测井进行了系统的布设,并提出了合理且有效的监控管理措施,从而为大型矿区地下水多源污染风险评价及长效监控机制提供理论依据。论文研究成果也可为我国类似矿区地下水多源污染风险评价及长效监控方案的布设提供有益参考。

With the rapid development of the national economy and the gradual improvement of the living standards, the demand for mineral resources intensified in our country. However, the environ-mental problems brought by mineral development increased significantly which affect the mine and surrounding groundwater environment seriously, especially in the decreasing of water table caused by mining and complex pollution sources formed by auxiliary project. Therefore, it’s ur-gently needed about the study of large-scale mining multi-source pollution risk and monitoring mechanism. This paper takes the Yuanzhu Ding Copper-Molybdenum Mine in Zhaoqing as research object, based on the analysis of mine hydrogeological conditions, generalized hydrogeological model reasonably. FEFLOW is used to construct numerical modeling which can predictive analysis the migration law of multi-source pollutants with or without water pumping and drainage of mine. It shows that the migration and proliferation of multi-source pollutants also like the natural groundwater runoff direction without water pumping and drainage of mine. On the contrary, the migration of polluters is controlled not only by natural groundwater flow, but it is also strongly influenced by water pumping and drainage of mine, which leads to the nearby pollutants carried to the working mining. Based on the mastery of the spatial migration law of multi-source pollutants, the long-term monitoring wells of groundwater in mining areas are systematically laid out, and reasonable and effective monitoring and management measures are put forward, thus it provides theoretical basis for risk assessment and long-term monitoring mechanism of multi-source pollution of groundwater in large mining areas. The research results could provide a useful refer-ence for the similar mining groundwater multi-source pollution risk assessment and long-term monitoring program establishment.