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

为加拿大大型流域开发创新的同位素耦合水文模型

• 批准号: RGPIN-2016-06043
• 负责人: Stadnyk, Tricia
• 金额: $ 1.75万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709797
• 关键词: Development; innovative; coupled; isotope; hydrologic

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.

最近人们认识到气候和水文学的非平稳性，因此需要更先进的流域模型来预测未来径流的变化以及对加拿大供水和安全的影响。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，其密度低于世界气象组织的最低测量网络标准。这项研究努力通过一种创新的同位素-水文耦合方法，为加拿大北部地区开发改进的水文预测工具。事实证明，耦合同位素排放测量在追踪与气候或土地利用不平稳性有关的下游水文变化方面特别有用。同位素在限制水文模型参数范围方面也是有用的诊断变量，但通常只在有观测数据的情况下使用。该计划的重点是isoWATFLOOD模型的创新和发展，这是一个完全分布式的水文模型，可以模拟和路由跨区域景观的水同位素。提出了isoWATFLOOD模式的关键创新，通过将降雪和融雪动力学以及氘同位素纳入蒸发模拟和蒸散发分配，提高了对高纬度偏远盆地的适用性。同位素示踪剂的模拟提供了一种手段来验证内部水文过程对水流的贡献，提高模拟水文的真实性，并确保适当的水文气候反馈。对这两种同位素的连续模拟还具有在大流域观测到的同位素记录中填补空白的优势，以及在未来气候条件下预测同位素信号的潜力。该模型将使用现有的同位素数据集在加拿大的两个泛北极盆地（Mackenize河和Nelson河下游）进行测试。将产生理论（模拟）同位素框架来验证蒸发和蒸散发分配。改进的融雪动力学模拟将显著改善年度水平衡模拟，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。在北方，基础设施设计、规划和建设中需要流量预测的部门，以及大坝结构的重新认证，将受到影响，因为极端流量事件的估计是必需的，但不再由测量记录来代表。结果是为加拿大的研究人员和水从业者需要先进的工具，以协助在气候变化下的流量预测。