Point physical model of movement of ions through natural snow cover

A one-dimensional physical model which simulates vertical movement of water and dissolved anions in snowpack was developed. The input information for this model is the meteorological data and the anion concentrations of preci pitation. The basic chemical and physical properties in different depths of the snow and their dynamic changes are the output from the model. The mode l was applied to the observed vertical profiles of snow density and anion c oncentrations obtained from the observation of natural snow cover for two w inter seasons. The changes in the observed vertical profile of snow density were well reproduced by the model, implying that the movement of water thr ough the snow cover is simulated properly by the model. The changes in the observed vertical profiles of chloride, sulfate and nitrate concentrations were also approximately reproduced. The physical properties of natural snow cover which affect the elution from snow were estimated by trial and error using the model. The results showed the validity of expressing the unsatur ated hydraulic conductivity, the water diffusivity and the hydrodynamic dis persion coefficient of natural snow cover as functions of water content and dry snow density. (C) 2000 Elsevier Science B.V. All rights reserved.