A physical SNOWPACK model for the Swiss avalanche warning Part I: numerical model
A physical SNOWPACK model for the Swiss avalanche warning Part I: numerical model
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DOI：
10.1016/s0165-232x(02)00074-5
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发表时间：
2002-11-01
影响因子：
4.1
通讯作者：
Lehning, M
中科院分区：
文献类型：
--
作者：
Bartelt, P;Lehning, M
给出了一维物理积雪模型的数值表示式。雪崩预警人员日常使用该模型来预测积雪的沉降、分层、地表能量交换和物质平衡。从位于雪崩起始区附近的自动气象站获得的气象数据被用作模型输入。本文给出了控制相变积雪的传热、水分传输、水蒸气扩散和机械变形的一维方程。将新雪、风漂移和雪烧蚀作为特殊的质量边界条件处理。雪被模拟为一种三组分(冰、水、空气)的多孔材料，能够经历巨大的不可逆粘性变形。模拟了各组分之间的相变。雪层的定义不仅要看高度和密度，还要看微观结构。也就是说，由组成冰晶格的颗粒的大小、形状和结合决定。控制方程采用全隐式拉格朗日-高斯-塞德尔有限元方法求解。给出了1999年雪崩灾害性冬季的实例计算，以证明模型的性能。总体质量平衡评估表明，该模式准确地预测了季节性高山积雪的积聚和消融。(C)2002 Elsevier Science B.V.保留所有权利。
The numerical formulation of a one-dimensional physical snowpack model is presented. The model is operationally employed on a day-to-day basis by avalanche warners to predict snowpack settlement, layering, surface energy exchange and mass balance. Meteorological data obtained from automatic weather stations positioned near avalanche starting zones is used as model input. In this paper, the one-dimensional equations governing the heat transfer, water transport, vapour diffusion and mechanical deformation of a phase changing snowpack are stated. New snow, wind drift and snow ablation are treated as special mass boundary conditions. Snow is modelled as a three-component (ice, water, air) porous material capable of undergoing large irreversible viscous deformations. Phase changes between the components are simulated. Snow layers are defined not only in terms of height and density, but also microstructure. That is, by the size, shape and bonding of the grains composing the ice lattice. The governing differential equations are solved using a fully implicit Lagrangian Gauss-Seidel finite-element method. Example calculations from the catastrophic avalanche winter 1999 are presented to document model performance. The overall mass balance evaluation shows that the model accurately predicts the build-up and ablation of the seasonal alpine snowcover. (C) 2002 Elsevier Science B.V. All rights reserved.