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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633997
• 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.

融雪是对加拿大大部分地区水资源的最大贡献，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月的艾伯塔省洪水是加拿大损失最大的自然灾害，损失达50亿美元，是由山雨雪过程造成的。2011年的大草原洪水由于积雪融化径流过多造成了20亿美元的损失，而2009-2013年的大干旱由于缺乏当地融雪径流和渗入造成了30亿美元的损失。更好地理解和预测降雪过程将有助于发展改进的旱涝预报技术、洪泛区制图和使用水文模型进行风险评估。本研究的目的是通过提高支持物理原理应用于水文预报模拟的知识来减少水文预报的不确定性。这项研究的地理焦点是加拿大落基山脉和草原。其目的是1)提高对垂直和水平雪量和能量交换过程的理解，包括雪上雨事件；2)更好地描述草、灌木和森林植被覆盖在调节积雪以及辐射和湍流通量方面的作用；3)提高对内部积雪能量和融水储存和释放的理解。加拿大落基山脉和草原地区的创新性野外观测方案与在水文模拟中部署的基本水文过程的数学模拟相结合，将用于研究具有很大不确定性的个别过程，例如雨落雪能量和径流、森林空地边缘和林线处的积聚和消融、积雪融化期间的平流、融水运动和沿山坡的径流形成，以及它们如何影响从小到盆地的雪水水文学。外地方案和计算机模拟将通过共同的外地地点，重点放在处理外地地点进程的水文过程和计算平台，为所有这三个目标作出贡献。这项研究将使用位于AB的加拿大落基山脉水文观测站(CRHO)和位于SK的Bright water Creek研究盆地(BCRB)的新的和已建立的研究站点，以详细的物理测量来补充基线测量。CRHO是位于萨斯喀彻温河流域源头的高海拔、重型仪器研究盆地的横断面。BCRB是萨斯卡通南部一个集约化的草原农业分水岭。短时间的密集观察期将用于过程研究；首先是堡垒山的晚期积雪，2012年和2013年艾伯塔省的雨雪洪水集中在那里。第二个将重点研究森林空地和林线上的积雪动力学。第三项研究将研究从草原和山区干燥和潮湿的表面到片状积雪的平流。第四项研究将检查深雪地区的融雪径流。为了将这些联系在一起，将使用寒冷地区水文学的计算机模拟来研究雨雪、融化能量平流、植被影响和融水通过积雪的流动，作为分水岭水文系统的一部分。改进的模型将作为模块在灵活、模块化的寒冷地区水文模拟平台中实施，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水分和径流预报。这一成果应能提高加拿大的旱涝预报能力，并能更好地管理山区水源和草原农业流域。