Water availability assessment in the Nelson River basin using a coupled water-isotope approach

能够准确模拟加拿大北部流域水循环变化的流域模型对于正确评估气候变化下的径流动态和对供水的潜在影响至关重要。也许最具挑战性的方面是传统上依赖稀疏水文数据网络的模型校准和参数化。气候变化和未来供水不确定性的影响在北纬地区被放大，因此马尼托巴省水电公司特别关注；纳尔逊河流域约占该省年发电量的75%，该省98%依赖水电。该项目将为马尼托巴省的水电行业提供工具、方法和人员，以便更准确地预测纳尔逊河下游流域流量和时间的变化。建议进一步开发和利用一种在等水文模拟系统(IsoWATFLOOD)中耦合水文和同位素数据的方法，以改进模型校准并减少未来水流模拟中的不确定性。稳定的水同位素是有效的示踪剂，因为河流排放中的信号很容易测量，并导致对水循环进行明确的系统标记。在五年期间，将培训11名高素质人员，并因该项目而对水文技术人员进行专门培训。改进的短期和长期流态变化的水文预测的结果将是改进的纳尔逊河下游的流量预测，用于实时和未来的研究，以优化系统容量、发电、电力交易和电力销售。经过适当校准的流域模型是设计、规划和建设拟建的未来发电站的重要组成部分，在这些发电站的水工建筑物尺寸确定时，需要对极端洪水进行估计，以确保来水设计洪水的安全通过。研究成果旨在通过最大限度地减少未来气候下水资源供应变化造成的潜在社会经济影响，减少马尼托巴省和加拿大对气候变化的脆弱性。

Watershed models capable of accurately simulating changes to the water cycle in northern Canadian watersheds are essential to correctly assess runoff dynamics and potential impacts to water supply under a changing climate. Perhaps the most challenging aspect becomes model calibration and parameterization that has traditionally relied on sparse hydrometric data networks. The effects of climate change and uncertainty in future water supply are magnified in northern latitudes and therefore are of particular concern to Manitoba Hydro; the Nelson River watershed represents ~75% of annual generation in a Province that is 98% reliant on hydropower. This project will provide the hydropower industry in Manitoba with the tools, methodology, and personnel to more accurately predict changes in the timing and quantity of flow in the lower Nelson River basin. Further development and utilization of an approach that couples hydrometric and isotopic data in an iso-hydrologic modelling system (isoWATFLOOD) is proposed to improve model calibration and reduce uncertainty in future flow simulations. Stable water isotopes are effective tracers since signals in river discharge are easily measured, and result in a well-defined systematic labelling of the water cycle. Over a five year period eleven highly-qualified personnel will be trained, with specialized training for hydrometric technicians as a result of this project. The outcome of improved hydrologic prediction of both short- and long-term changes in the flow regime will be improved flow prediction in the lower Nelson River that will be used for real-time and future studies to optimize system capacity, power generation, power trading, and power sales. Properly calibrated watershed models are an essential component to the design, planning, and construction of proposed future generating sites where estimates of extreme floods are required in the sizing of hydraulic structures to ensure safe passage of the inflow design flood. Research outcomes are intended to reduce Manitoba and Canada's vulnerability to climate change by minimizing potential socio-economic impacts resulting from changing water availability under future climates.