The impact of mine dewatering on the hydrology and mercury bioeochemistry of peatlands in the Hudson / James Bay lowland: The De Beers Victor Diamond Mine

安大略省阿塔瓦皮斯卡特附近的钻石开采作业定于2008年初开始。超过90%的地区被泥炭地（muskeg）覆盖。矿井的脱水将从下面的渗透性石灰岩含水层中抽出水，这可能导致或加速水从地表系统向下渗透，并部分排干约3000平方公里的泥炭地。我们预计与上下水文系统之间的连接强度有关的不同的空间排水模式。相对具有渗透性的生物礁（古珊瑚礁）从基岩含水层穿过泥炭地下面的细颗粒沉积层突出到地表，有望提供渗透的“窗口”。在泥炭地发生部分排水的地方，生态系统将发生变化，特别是植被模式。戴比尔斯为一项研究项目提供了大量资金，该项目旨在探索和记录地表（泥炭地）和深层（石灰石）含水层系统之间的水文地质联系。目前的提案建立在该研究的基础上，1)更详细地检查泥炭地排水系统（地下水位、土壤湿度、流动路径），这样我们就可以构建一个包括一系列泥炭地类型的水预算；2)研究该系统中的汞动力学，因为我们怀疑这种干扰会导致天然存在的汞甲基化，从而使其释放到地表水中；3)通过增加遥感组件来扩大干扰监测的规模，该组件将检测对水敏感的植被群落和泥炭地表面配置的变化，从而使我们能够解释采矿活动的更广泛的影响和响应。

Diamond mining operations near Attawapiskat, Ontario are set to begin in early 2008. Over 90% of this area is covered by peatlands (muskeg). Dewatering of the mine will pull water from the underlying permeable limestone aquifer that could cause or accelerate downward seepage of water from the surface system, and partially drain about 3000 km2 of peatland. We anticipate distinct spatial patterns of drainage related to the strength of the connection between the upper and lower hydrological systems. Relatively permeable bioherms (ancient coral reefs) that protrude to the surface from the bedrock aquifer through the layer of fine-grained sediments that directly underlie the peatland, are expected to provide "windows" of seepage. Where partial drainage of peatland occurs the ecosystem will change, notably the vegetation patterns. DeBeers has made a substantial financial contribution to a research project which aims to explore and document the hydrogeological linkages between the surface (peatland) and deep (limestone) aquifer systems. The current proposal builds on that research by 1) examining in more detail the peatland drainage systems (water table, soil moisture, flow pathways) so we can construct a water budget that includes a range of peatland types; 2) investigating the mercury dynamics in this system, since we suspect that the disturbance will cause methylization of the naturally occurring mercury, hence its liberation into surface waters; and 3) expanding the scale of disturbance-monitoring with the addition of a remote sensing component which will detect changes in water-sensitive vegetation communities and peatland surface configurations - and thus allow us to interpret the broader impacts and responses of the mining activity.