Stable Water Isotope Study of a Mesoscale Precambrian Shield Basin for Improved Model Predictions of Water Quantity and Quality

研究流域内的水循环对于提高我们预测人类活动（如城市和农业土地利用、气候变化）对淡水资源影响的能力至关重要。从区域上看，前寒武纪盾状湖显示出越来越多的有害藻华（HABs），而营养输入（如磷）和气候条件可能是促成因素。计算机模型是帮助预测未来对水资源影响的主要工具，但它们的使用存在很大的不确定性。水循环研究可以对水如何储存和释放到我们的水道产生重要的见解，从而改进这些模型。最近的技术降低了成本，提高了分析水分子中氧和氢同位素的水和蒸汽样品的能力。自然存在的水同位素比率可以区分水流中水源的混合（如融雪、地下水）和蒸发的影响，这在与流域管理和决策相关的尺度上提供了重要水文过程的新证据。尼皮辛湖和法国河是一个重要的源头支流的一部分，流入格鲁吉亚湾。该湖及其13,000平方公里的流域是当地市政当局和第一民族社区的水源，是第一民族渔业和安大略省5%的休闲垂钓的所在地，每年为安大略省的经济贡献约1亿美元。该研究项目设在尼皮辛大学新的流域分析中心，将应用水同位素技术来提高对鲟鱼河-尼皮辛湖-法兰西河（SNF）流域水运动的了解。它将具体评价融雪、地下水和地表水（如湖泊、湿地、水库）在高流量和低流量期间以及数年内对季节性流量的贡献，并捕捉投入的年际和年内变化。将评估景观特征（地质、土壤、地形、自然和人为引起的土地覆盖/利用）对水流产生的影响。SNF盆地的发现将为人类活动（城市化、农业活动）显著影响的前寒武纪盾状盆地的水循环提供新的见解，并推进对水循环影响评估的研究方法，这些研究方法将用于改进对未来淡水资源的大规模预测。

The study of the cycling of water through our watersheds is critical to improve our ability to predict the impact of human activities (e.g. urban and agricultural landuse, climate change) on freshwater resources. Regionally, Precambrian shield lakes are showing an increasing number of harmful algae blooms (HABs) with nutrient inputs (e.g phosphorus) and climate conditions likely contributing factors. Computer models are primary tools that help predict future impacts on water resources but their use comes with large uncertainties. Water cycling studies can generate important insights into how water is stored and released to our waterways, improving these models. Recent technology has reduced the cost and improved the ability to analyze water and vapor samples for isotopes of oxygen and hydrogen of the water molecule. Ratios of naturally occurring water isotopes can distinguish the mixture of water sources in streamflow (e.g. snowmelt, groundwater) and the influence of evaporation which provides new evidence of important hydrological processes at scales relevant to watershed management and decision making. Lake Nipissing and the French River are part of an important headwater tributary that flows into Georgian Bay. The lake, and its 13,000 km2 watershed is the source of water to local municipalities and First Nation communities, home to a First Nations fishery and 5% of Ontario's recreational angling, and contributes an estimated $100 million/year to Ontario's economy. Based at Nipissing University's new Watershed Analysis Centre, this research program will apply water isotope technology to improve understanding of water movement in the Sturgeon River-Lake Nipissing-French River (SNF) basin. It will specifically evaluate contributions of snowmelt, groundwater and surface water (e.g. lakes, wetlands, reservoirs) to seasonal streamflow during high and low flows and over several years, capturing inter- and intra-year variability in inputs. The influence of landscape characteristics (geology, soils, topography, natural and human-induced landcover/use) on streamflow generation will be assessed. Findings from the SNF basin will provide new insights into water cycling for Precambrian shield basins with significant influences of anthropogenic activities (urbanization, agricultural activity) and advance research approaches in assessing impacts on water cycling that will be used for improved predictions of the future of our freshwater resources on a broad scale.