Evaluating the impacts of mine dewatering and flooding on peatlands

采矿活动涉及减轻对环境的影响，对加拿大强劲的经济发展至关重要。然而，泥炭地退化和矿井降水/洪水之间的联系还不是很清楚。环境评估方面的这一差距可能会导致重大的环境和财务影响。该计划针对的是预先确定的问题。长期总体目标是开发新的方法来评估矿山降水/洪水对泥炭地的影响。具体目标(SO)是：(1)评价泥炭地对矿山降水的水文响应；(2)评价泥炭地对矿山降水的地球化学响应；(3)模拟矿山降水/洪水对泥炭地水文和化学平衡的影响。目标泥炭地位于Agnico-Eagle Akasaba-West工地(昆士兰州Abitibi)附近，预计将于2018/2019年开始露天开采。SO1(MSc1)侧重于建立水预算。测压仪将安装在测压仪的巢穴中，用于监测饱和和非饱和泥炭中的水位和温度。还将监测与泥炭地相连的溪流中的流量和温度波动。这些数据将使人们能够史无前例地评估基岩含水层上方的泥炭地因矿井降水而降压的水文反应。二氧化硫(MSc2)侧重于建立地球化学预算。泥炭孔隙水(来自测压仪巢)和溪流样本的地球化学将在一年内进行监测。还将监测现场的物理化学参数(包括Eh和pH)。分析计划将侧重于评估三种主要的氧化还原和pH敏感元素(锰、铁、砷)的浓度和形态，以及它们与水的稳定同位素(2H、17O、18O)和溶解有机碳含量变化的联系。将对地球化学和水文数据进行联合解释，以评估受矿井降水影响地区泥炭地水文和地球化学平衡之间的联系。SO3(Phd1)专注于建模。将使用SEEP/W进行瞬时水文模拟。将使用PHREEQC和地球化学家工作台评估As的形态。将使用CTRAN/W模拟砷的运输。模拟将按照系统的参数方法进行，以测试各种矿山降水/洪水情景对泥炭地的影响。该项目将提供了解泥炭地对采矿的敏感性所需的新数据。这种将物理、化学和同位素数据与建模相结合的方法是原创的，与采矿业和科学界高度相关。目标矿场预计将于2018/2019年开始运营：同步启动该计划有一个独特的机会。

Mining activities, which involve the mitigation of environmental impacts, are essential to the strong economic development of Canada. Nevertheless, the links between peatland degradation and mine dewatering/flooding are not well understood. This gap in environmental assessments can lead to major environmental and financial impacts. This program targets the pre-established issue. The long-term general objective is to develop novel approaches for evaluating the impacts of mine dewatering/flooding on peatlands. The specific objectives (SO) are (1) to assess the hydrological response of a peatland to mine dewatering, (2) to evaluate the geochemical response of a peatland to mine dewatering and (3) to simulate mine dewatering/flooding impacts on peatland hydrological and chemical balance. The targeted peatland is located near the Agnico-Eagle Akasaba-West site (Abitibi, QC), where open-pit mining is expected to begin in 2018/2019. SO1 (MSc1) focuses on establishing a water budget. Loggers will be installed in piezometer nests and in the acrotelm for monitoring water levels and temperature within the saturated and unsaturated peat. Discharge and temperature fluctuations in the stream connected to the peatland will also be monitored. The data will allow an unprecedented evaluation of the hydrological response of a peatland overlying a bedrock aquifer undergoing depressurization owing to mine dewatering. SO2 (MSc2) focuses on establishing a geochemical budget. The geochemistry of peat pore water (from piezometer nests) and stream samples will be monitored during one year. In situ physicochemical parameters (including Eh and pH) will also be monitored. The analytical program will focus on the evaluation of the concentration and speciation of three main redox and pH sensitive elements (Mn, Fe, As) and on their links with variations in the stable isotopes of water (2H, 17O, 18O) and in dissolved organic carbon contents. The geochemical and hydrological data will be interpreted jointly to evaluate the linkages between peatland hydrological and geochemical balance in an area affected by mine dewatering. SO3 (PhD1) focuses on modeling. Transient hydrological simulations will be carried out using SEEP/W. The speciation of As will be evaluated using PHREEQC and Geochemist's Workbench. The transport of As will be simulated using CTRAN/W. Simulations will be conducted following a systematic parametric approach for testing the impacts of various scenarios of mine dewatering/flooding on the peatland. The program will provide novel data needed to understand the sensitivity of peatlands to mining. The approach, coupling physical, chemical and isotopic data with modeling, is original and highly relevant for the mining industry and the scientific community. The targeted mining site is expected to start operating in 2018/2019: there is a unique opportunity to initiate the program synchronously.