Development of an innovative coupled isotope-hydrologic model for large Canadian watersheds

最近认识到气候的非平稳性，因此水文，需要更先进的流域模型来预测未来径流的变化和对加拿大供水的影响，因此安全。在加拿大，大部分水位于高纬度地区，那里的流域建模能力和准确性受到稀疏的水文气象网络的阻碍，密度低于世界计量组织最低计量网络标准。 这项研究致力于开发改进的水文预测工具，北方加拿大制度，通过创新的耦合同位素水文方法。耦合同位素排放测量已被证明是特别有用的跟踪渐进下游水文变化有关的气候或土地利用的非平稳性。 同位素也是有用的诊断变量，在约束水文模型参数范围，但通常只适用于ad-hoc时，并在观测数据可用。该计划的重点是创新和isoWATFLOOD模型的发展，这是一个完全分布式的水文模型，模拟和路由跨区域景观的水同位素。isoWATFLOOD模型的主要创新，提出了将雪和融雪动力学和氘同位素蒸发建模和蒸散分区，以提高高纬度，偏远流域的适用性。同位素示踪剂的模拟提供了一种手段，以验证内部水文过程的贡献，径流，提高模拟过程的真实性，并确保适当的水文气候反馈。两种同位素的连续模拟还具有在大型河流流域中观测到的同位素记录的“填补空白”的优点，以及在未来气候下同位素信号预测的潜力。该模型将在两个泛北极加拿大盆地与现有的同位素数据集（Mackenize和较低的纳尔逊河）进行测试。 将产生理论（模拟）同位素框架，以验证蒸发和蒸散分配。 融雪动力学模拟的改进将显著提高年度水平衡模拟，因为融雪代表了这些流域每年最大的流量。研究将为水文模拟提供新的工具和HQP专业培训，目标是在没有额外现场仪器的情况下改善大型河流的模拟。北方基础设施设计、规划和建设需要径流预测的部门以及大坝结构的重新认证将受到影响，因为需要对极端流量事件进行估计，但不再由计量记录表示。 成果是为加拿大研究人员和需要先进工具的水从业人员准备的，以协助在气候变化下进行径流预测。**

Recent recognition of non-stationarity in climate, and consequently hydrology, is requiring more advanced watershed models to project changes in future runoff and the impacts to Canada's water supply and therefore security. In Canada, much of the water resides at high latitudes where watershed modelling capabilities and accuracies are hindered by sparse hydro-meteorological networks, with densities below World Metrological Organization minimum gauging network standards. This research endeavours to develop improved hydrologic prediction tools for northern Canadian regimes through an innovative coupled isotope-hydrometric approach. Coupled isotope-discharge measurement has proven particularly useful in tracing progressive downstream hydrologic change related to climate or land-use non-stationarity. Isotopes are also useful diagnostic variables in constraining hydrologic model parameter ranges, but have typically been applied ad-hoc only when and where observational data is available. The proposed program focuses on innovation and development of the isoWATFLOOD model, a fully distributed hydrological model that simulates and routes water isotopes across regional landscapes. Key innovations of the isoWATFLOOD model are proposed to enhance applicability to high-latitude, remote basins by incorporating snow and snowmelt dynamics and the deuterium isotope for evaporation modelling and evapotranspiration partitioning. Simulation of the isotope tracers provides a means to validate internal hydrologic process contributions to streamflow, improving the realism of simulated hydrographs and ensuring proper hydroclimatic feedbacks. Continuous simulation of both isotopes also has the advantage of gap-filling' observed isotope records in large river basins, and the potential for isotope signal projection under future climates. The model will be tested in two pan-arctic Canadian basins with existing isotope datasets (Mackenize and lower Nelson Rivers). Theoretical (simulated) isotope frameworks will be produced to validate evaporation and evapotranspiration partitioning. Improved simulation of snowmelt dynamics will significantly improve annual water balance simulations since snowmelt represents the largest flow volume on an annual basis for these basins. Research will provide new tools and HQP with specialized training in hydrologic simulation, with the goal of improving simulation in large rivers without additional field instrumentation. Sectors requiring streamflow projection for infrastructure design, planning, and construction in the North, and recertification of dam structures will be impacted as estimates of extreme flow events are required but no longer represented by gauged records. Outcomes are intended for Canadian researchers and water practitioners requiring advanced tools to assist in streamflow projection under climate change. **