采动影响下矿区深部地下水循环氢氧稳定同位素示踪

Hydrogen and Oxygen Stable Isotope Tracing of Deep Groundwater Circulation under Mining-Induced Disturbance in Mining District

为了揭示开采扰动影响下深部地下水循环机制,准确预测井下开采充水类型,以淮北煤田宿-临矿区为研究示范,采用氢氧稳定同位素示踪技术,分析矿区地下水循环过程、补给来源,从而确定地下水混合的线性端元,进而开展地下水线性端元混合比例的计算。研究结果表明:在含水层补给区沿地下水径流方向δ值降低,在径流区或排泄区δ值较为恒定;矿区地下水混合的线性端元为大气降水直接入渗水、滞留入渗水以及古地下水;由于开采充水影响,矿区主要充水含水层线性端元混合比例相差较大。因此,只有通过确定地下水线性端元混合比例的动态变化趋势,才能推测煤矿开采进程中充水来源,为矿井突水预测预报与地下水资源保护提供理论依据。

In order to reveal the circulation mechanism of deep groundwater under mining-induced disturbance,thus accurately predict the type of water inrush,hydrogen and oxygen stable isotope tracing technique is adopted in this study in Su-Lin Mining District in Huaibei coalfield,to analyze the circulation process and recharge sources of groundwater in mining area,and to determine the groundwater mixing linear endmembers and calculate its mixing ratio.The research results show that：the value of δ decreases along the groundwater flow direction in the aquifer recharge area,yet it is constant in runoff or discharge areas;the mixing linear endmembers in mining area are direct infiltration water of precipitation,retained infiltration water or palaeo-water;the mixing ratio of linear endmembers is quite different because of mining-induced disturbance and water inrush.Therefore,only when the dynamic change trend has been determined,the water inrush source during mining can be well speculated.Finally,the theoretical basis for the prediction of mine water inrush and the protection of groundwater resource can be provided.