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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567877
• 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最重要的贡献，因此不仅对加拿大的水安全至关重要，而且构成了气候变化对加拿大生态系统、社区和经济的许多影响的基础。 2013 年 6 月的艾伯塔省洪水是加拿大损失最惨重的自然灾害，造成的损失超过 50 亿美元，主要是由山区雨雪过程造成的。由于融雪径流过多，2011 年的草原洪水造成了超过 20 亿美元的损失；由于当地融雪径流和渗透不足，2009-2013 年的大干旱造成了超过 30 亿美元的损失。更好地理解和预测降雪过程将有助于开发改进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。这项研究的目的是通过提高支持物理原理模拟应用的知识来减少水文预测的不确定性。这项研究的地理重点是加拿大落基山脉和大草原。目标是 1) 提高对垂直和水平雪量和能量交换过程（包括雨雪事件）的了解，2) 更好地描述草、灌木和森林植被覆盖在改变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以及融水储存和释放的了解。 加拿大落基山脉和大草原的创新实地观测计划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，将用于检查具有很大不确定性的个别过程，例如雨雪能量和径流、森林空地边缘和林线的积聚和消融、斑块融雪期间的平流以及沿线的融水运动和径流形成 山坡及其如何影响从小到盆地尺度的雪水文。现场计划和计算机建模将通过共同现场站点，重点关注水文过程和解决现场过程的计算平台，为所有三个目标做出贡献。 该研究将利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，以详细的物理测量来补充基线测量。 CRHO 是萨斯喀彻温河流域源头的一个高海拔、仪器仪表齐全的研究盆地横断面。 BCRB 是萨斯卡通以南一个设施齐全的草原农业流域。将利用较短的密集观察期来重点进行过程研究；首先是 Fortress Mountain 的晚积雪，这里是 2012 年和 2013 年艾伯塔省雨雪洪水的集中地。第二个将重点关注森林空地和林线处的积雪动态。第三个项目将研究草原和山区干燥和潮湿表面对片状积雪的平流作用。第四个项目将检查深雪地区的融雪径流。 为了将其结合起来，寒冷地区水文学的计算机模拟将用于研究雨雪、融水能量的平流、植被影响以及作为流域水文系统一部分的融水流经积雪。改进的模型将作为灵活的模块化寒冷地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对山区和草原土壤湿度和径流预测的改进程度。研究结果将提高加拿大的洪水和干旱预报能力，并更好地管理山区源头和草原农业流域。