Improved Methods for Determining Soil-Atmosphere Flux Boundary Conditions at Mine Waste Repositories

矿山废物储存库的成功运作和关闭需要准确量化控制大气水渗入废物剖面的地表水预算。净表面渗透的速率最终产生内部渗流，释放潜在的渗滤液，可能威胁下游受体。最近在加拿大的活跃矿区和再生矿区以及加拿大公司经营的国际矿区进行的实地规模观察表明，目前用于计算诸如废石堆和尾矿库等矿山废物沉积物渗透率的预测模型是不可接受的。例如，根据不列颠哥伦比亚省Equity银矿排水收集沟渠中测量的流量直接确定的净入渗率已被发现比使用当前土壤-大气模拟方法预测的入渗率高出三倍。这里提出的研究计划的总体目标是调查这些误差的原因，并改进现有的土壤-大气方法，目前可用于估计矿山废物库的地表通量边界条件。

Successful operation and closure of mine waste repositories require accurate quantification of the surface water budget that controls the infiltration of meteoric water into the waste profile. The rate of net surface infiltration ultimately generates internal seepage with the release of potential leachates that may threaten downstream receptors. Recent field scale observations at both active and reclaimed mine sites in Canada, as well as international sites operated by Canadian companies, have shown current predictive models used to calculate infiltration rates for mine waste deposits such as waste rock dumps and tailings impoundments are unacceptable. For example, net infiltration rates determined directly on the basis of measured flow rates in the drainage collection ditches at Equity Silver mine in British Columbia have been found to be three fold greater than infiltration rates predicted using the current soil-atmosphere modelling methodology. The global objective of the research program proposed here is to investigate the reasons for these errors and to improve the existing soil-atmosphere methods currently available for estimating surface flux boundary conditions at mine waste repositories.