Abstract

Annual precipitation, temperature, and the frequency and duration of drought events are expected to increase in Québec (Canada) south of the 50th parallel as a result of climate change. Oxygen barriers such as covers with capillary barrier effects (CCBE), which are used to control acid mine drainage (AMD), are sensitive to climate change. Increases in precipitation may have positive effects on maintaining the saturation of a moisture-retaining layer (MRL), which is necessary for reducing oxygen fluxes to reactive tailings; however, drought events could cause temporary desaturation of a MRL and, consequently, increase the potential for acid generation. The Lorraine mine site, in western Québec, was reclaimed with a CCBE in 1999 and was used as a case study to assess the effects of climate change on reclamation performance. A two-dimensional numerical model was developed and validated using 3 years of meteorological and hydrogeological data. Numerical simulations were performed to assess the CCBE’s performance, considering the influence of: (1) climatic conditions (i.e., precipitation, temperature, relative humidity, wind speed, albedo and solar radiation) by 2100 for three different climate-change scenarios, and (2) extreme drought events. Performance targets were reached for all tested climate-change scenarios, thus indicating that the Lorraine CCBE design is robust with respect to climate change and extreme droughts. More broadly, this study illustrates how numerical simulations can be used to quantify the influence of climate change on the long-term ability of CCBEs to control the generation of AMD.

中文翻译：

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气候变化对带有毛细屏障作用的覆盖物控制酸生成能力的影响

摘要

由于气候变化，魁北克（加拿大）第50纬线以南的年降水量，温度以及干旱事件的频率和持续时间预计将增加。氧气屏障，例如具有毛细屏障效应的覆盖物（CCBE），用于控制酸性矿山排水（AMD），对气候变化敏感。降水增加可能对保持水分保持层（MRL）的饱和有积极作用，这对于减少流向反应性尾矿的氧气通量是必要的；但是，干旱事件可能会导致MRL暂时饱和，从而增加产酸的潜力。魁北克西部的洛林矿区于1999年通过CCBE进行了开采，并用作案例研究来评估气候变化对开垦性能的影响。使用三年的气象和水文地质数据，开发并验证了二维数值模型。考虑到以下因素的影响，进行了数值模拟以评估CCBE的性能：（1）到2100年针对三种不同的气候变化情景的气候条件（即降水，温度，相对湿度，风速，反照率和太阳辐射），以及（ 2）极端干旱事件。在所有经过测试的气候变化情景中均达到了性能指标，因此表明，洛林CCBE设计在应对气候变化和极端干旱方面非常可靠。更广泛地说，这项研究说明了如何使用数值模拟来量化气候变化对CCBEs控制AMD产生的长期能力的影响。