New approaches to address scaling issues for lateral flow of water in a layered snowpack

Ryan W. Webb博士获得了美国国家科学基金会EAR博士后奖学金，将在科罗拉多大学博尔德分校和劳伦斯伯克利国家实验室开展研究和教育计划。韦伯博士将致力于更好地了解积雪中水的横向流动。研究者将研究雪中毛细血管和/或渗透性屏障的形成和尺度，以及实验室尺度参数作为建模输入的适用性。这项调查将为多种环境下春季融雪期间发生的水文过程提供基本的见解。这项研究产生的数据将通过水文数据库CUAHSI HIS广泛提供。除了研究之外，研究者还将参与教育活动，如指导本科生和研究生进行大量的研究机会，并在科罗拉多大学共同教授一门水文学课程。在融雪过程中发生的动态过程创造了一个复杂的环境，在这个环境中，水的横向流动已被证明具有重要的水文意义，尽管难以建模。为了准确地模拟这一过程，在适当的尺度上表示积雪特性是必要的。因此，本研究力求：1)确定在山坡尺度上产生显著横向流动所需的相邻积雪层之间粒度和密度的变化，2)确定产生这些屏障所需的驱动物理（地形、土地覆盖等）和气候条件，3)生成能够模拟具有时间变化性质的层状多孔介质的二维数值模型。4)确定实验室尺度的雪性质研究是否适用于山坡尺度的应用。数据将在Boulder Creek CZO和Niwot Ridge LTER的海拔梯度上收集，使用最新的全球定位系统和探地雷达方法对雪中的液态水含量进行无损测量，染料示踪剂实验用于更大规模的流动路径发展调查，隔离斜坡影响的实验室实验，以及对先前开发的实验室尺度参数进行逆建模。

Dr. Ryan W. Webb has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at the University of Colorado - Boulder and Lawrence Berkeley National Laboratory. Dr. Webb will aim at better understanding the lateral flow of water within a snowpack. The investigator will study the formation and scales at which capillary and/or permeability barriers occur in snow, and the applicability of laboratory scale parameters as input for modeling. The investigation will provide fundamental insights into hydrological processes that occur during spring snowmelt in multiple environments. Data generated from this research will be made widely available through the hydrologic database CUAHSI HIS. In addition to research, the investigator will engage in education activities like mentoring undergraduate and graduate students in numerous research opportunities and co-teaching a hydrology course at the University of Colorado.The dynamic processes that occur during snowmelt create a complex environment where the lateral flow of water has been shown to be hydrologically significant, though difficult to model. To model this process accurately, representation of snowpack properties at appropriate scales is necessary. Thus, the research seeks to: 1) determine the variability in grain size and density between adjacent snowpack layers required to produce significant lateral flow at the hillslope scale, 2) determine the driving physical (topographic, land cover, etc.) and climatic conditions required to produce these barriers, 3) produce a two-dimensional numerical model capable of simulating layered porous media with temporally varying properties, and 4) determine how suitable laboratory scale investigations of snow properties are for applications at the hillslope scale. Data will be collected across elevation gradients in the Boulder Creek CZO and Niwot Ridge LTER using state of the science Global Positioning Systems and Ground Penetrating Radar methods for non-destructive measurements of liquid water content in snow, dye tracer experiments for larger scale flow path development investigations, laboratory experiments for isolation of the effect of slope, and inverse modeling for upscaling previously developed laboratory scale parameters.