We present here the first comprehensive assessment of the carbon (C) footprint associated with the creation of a boreal hydroelectric reservoir (Eastmain-1 in northern Québec, Canada). This is the result of a large-scale, interdisciplinary study that spanned over a 7-years period (2003–2009), where we quantified the major C gas (CO2 and CH4)sources and sinks of the terrestrial and aquatic components of the pre-flood landscape, and also for the reservoir following the impoundment in 2006. The pre-flood landscape was roughly neutral in terms of C, and the balance between pre- and post-flood C sources/sinks indicates that the reservoir was initially (first year post-flood in 2006) a large net source of CO2 (2270 mg C m-2 d-1) but a much smaller source of CH4 (0.2 mg C m-2 d-1). While net CO2 emissions declined steeply in subsequent years (down to 835 mg C m-2 d-1 in 2009), net CH4 emissions remained constant or increased slightly relative to pre-flood emissions. Our results also suggest that the reservoir will continue to emit carbon gas over the long-term at rates exceeding the carbon footprint of the pre-flood landscape, although the sources of C supporting these emissions have yet to be determined. Extrapolation of these empirical trends over the projected life span (100 years) of the reservoir yields integrated long-term net C emissions per energy generation well below the range of the natural-gas combined-cycle, which is considered the current industry standard.
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机译:我们在此首次提出与北部水力发电库(加拿大魁北克省北部的Eastmain-1)相关的碳足迹的综合评估。这是一项为期7年(2003-2009年)的跨学科大规模研究的结果,在该研究中,我们量化了前陆平原陆地和水生组分的主要C气(CO2和CH4)源和汇。洪水景观,以及2006年蓄水后的水库景观。洪水前的C值大致为中性,并且洪水前和洪水后C源/汇之间的平衡表明水库最初是( 2006年洪灾后的第二年),二氧化碳的净排放量较大(2270 mg C m-2 d-1),而甲烷排放量较小(0.2 mg C m-2 d-1)。尽管随后的几年中二氧化碳的净排放量急剧下降(2009年降至835 mg C m-2 d-1),但甲烷的净排放量相对于洪水前的排放量保持不变或略有增加。我们的结果还表明,尽管仍需确定支持这些排放的碳源,但从长远来看,该储层将继续以超过驱前地形碳足迹的速率排放碳气。通过对油藏预计寿命(100年)内的这些经验趋势进行推断,可以得出每能源产生的长期总净碳排放量远低于天然气联合循环的范围(被认为是当前行业标准)。
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