Snow Hydrology

雪水文

• 批准号: RGPIN-2014-06543
• 负责人: Pomeroy, John
• 金额: $ 5.25万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=612289
• 关键词: Snow; Hydrology

Snowmelt is the most significant contribution to water resources in most of Canada and so is not only vital to Canada’s water security, but forms the basis for many impacts of climate change on Canadian ecosystems, communities and economies. The Alberta Flood of June 2013 was Canada’s most expensive natural disaster, with costs >$5 billion, and was contributed to by mountain rain-on-snow processes. The Prairie floods of 2011 cost >$2 billion due to excess snowmelt runoff and the Great Drought of 2009-2013 cost >$3 billion due to lack of local snowmelt runoff and infiltration. Better understanding and prediction of snow processes will contribute to the development of improved flood and drought forecasting techniques, floodplain mapping and risk assessment using hydrological models.The objective of this research is to reduce uncertainty in hydrological prediction by improving the knowledge that underpins the application of physical principles to its simulation. The geographical focus of this research is the Canadian Rockies and Prairies. The goals are to 1) improve the understanding of vertical and horizontal snow mass and energy exchange processes, including rain-on-snow events, 2) better describe the role of grass, shrub and forest vegetation cover in modifying snow accumulation and the radiative and turbulent fluxes, 3) improve the understanding of internal snowpack energy and meltwater storage and release. A combination of innovative field observation programmes in the Canadian Rockies and Prairies with advances in mathematical simulations of the fundamental hydrological processes deployed in hydrological simulations will be used to examine individual processes of great uncertainty such as rain-on-snow energetics and runoff, accumulation and ablation at edges of forest clearings and at treelines, advection during patchy snowmelt, and meltwater movement and runoff formation along hillslopes and how they affect snow hydrology from small to basin scales. The field programme and computer modelling will contribute to all three objectives through common field sites, a focus on hydrological processes and computational platforms addressing the processes at the field sites. The study will use new and established research sites in the Canadian Rockies Hydrological Observatory (CRHO), AB and the Brightwater Creek Research Basin (BCRB), SK to supplement baseline measurements with detailed physical measurements. The CRHO is a transect of high-elevation heavily instrumented research basins in the headwaters of the Saskatchewan River Basin. The BCRB is an intensively-instrumented prairie agricultural watershed south of Saskatoon. Short intensive observation periods will be used to focus on process research; first on late-lying snowpacks at Fortress Mountain where the 2012 & 2013 Alberta rain-on-snow floods were centred. A second will focus on snow dynamics in forest clearings and at treelines. A third will examine advection to patchy snowpacks from dry and wet surfaces in prairies and mountains. The fourth will examine snowmelt runoff from deep snow sites. To tie this together, computer simulations of cold regions hydrology will be used to study rain-on-snow, advection of melt energy, vegetation impacts and meltwater flow through snowpacks as part of the watershed hydrological system. Improved models will be implemented as modules in the flexible, modular Cold Regions Hydrological Modelling platform to determine the degree to which soil moisture and streamflow predictions in the mountains and prairies are improved by these new snow process descriptions. The results should improve Canada's flood and drought forecast capabilities and allow for better management of mountain headwater and prairie agricultural watersheds.

融雪是加拿大大部分地区水资源的最重要贡献，因此不仅对加拿大的水安全至关重要，而且是气候变化对加拿大生态系统、社区和经济产生许多影响的基础。2013年6月的阿尔伯塔洪水是加拿大最昂贵的自然灾害，损失超过50亿美元，是由山区雨雪过程造成的。2011年的大草原洪水由于过度的融雪径流造成的损失超过20亿美元，2009-2013年的大干旱由于缺乏当地的融雪径流和渗透造成的损失超过30亿美元。更好地了解和预测降雪过程将有助于开发更好的洪水和干旱预报技术，洪泛区绘图和利用水文模型进行风险评估，本研究的目的是通过提高支持将物理原理应用于水文预测模拟的知识，减少水文预测中的不确定性。本研究的地理重点是加拿大落基山脉和大草原。其目标是：1）提高对垂直和水平雪质量和能量交换过程的理解，包括雨对雪事件，2）更好地描述草，灌木和森林植被覆盖在修改积雪和辐射和湍流通量的作用，3）提高对内部积雪能量和融水储存和释放的理解。 加拿大落基山脉和大草原的创新性实地观测方案与水文模拟中部署的基本水文过程数学模拟的进展相结合，将用于研究具有很大不确定性的个别过程，如雨雪能量学和径流、森林空地边缘和树木线的积累和消融、不均匀融雪期间的平流、和融水运动和径流形成沿着山坡和他们如何影响雪水文从小到流域尺度。实地方案和计算机建模将通过共同实地地点、侧重水文过程和处理实地过程的计算平台，为所有三个目标作出贡献。 该研究将使用加拿大落基山脉水文观测站（CRHO），AB和Brightwater Creek研究盆地（BCRB），SK的新的和已建立的研究站点，以补充详细的物理测量基线测量。CRHO是萨斯喀彻温河流域源头的高海拔重仪器研究流域的一个横断面。BCRB是萨斯卡通南部的一个密集仪器化的草原农业流域。短时间的密集观测将用于过程研究;首先是2012年和2013年阿尔伯塔雨雪洪水集中的堡垒山的后期积雪。第二个将集中在森林空地和树木线的雪动力学。第三个实验将研究从草原和山区的干燥和潮湿表面到片状积雪的平流。第四个项目将检查深雪区的融雪径流。 为了将这一点联系在一起，寒冷地区水文学的计算机模拟将被用来研究雨对雪，融化能量的平流，植被的影响和融水流经积雪作为流域水文系统的一部分。改进后的模型将作为灵活的模块化寒区水文建模平台中的模块实施，以确定这些新的降雪过程描述在多大程度上改善了山区和草原的土壤湿度和径流预测。研究结果将提高加拿大的洪水和干旱预测能力，并使其能够更好地管理山区水源和草原农业流域。