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

点击翻译按钮获取中文摘要

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.