Cartography of snowcover properties from topographical, vegetation and meteorological data.

摘要

A Multi Layer Snow Accumulation Model (MLSAM) was developed to simulate snow cover properties. The simulations include snow depth, snow density and snow-cover. The model was tested near Schefferville (54°48'N, 66°49'W) for the years (1986-1987 and 1987-1988). The MLSAM combines three sub models: 1) An intermediate-complexity, quasi-physically based, meteorological model (MicroMet), 2) A Point Energy/Mass Balance (PEMB) model and 3) A Distributed Blowing Snow Model (DBSM). The MLSAM employs digital terrain models with grid increments of 20 m and run with temporal increments of 24 hours using standard Canadian digital elevation and vegetation models and climate data.;The model outputs for snow-layer depth and density as well as snow cover remaining at different times during the melt season were compared with available data from the Schefferville climate station and from previous snow research at Schefferville. Landsat images were used for assessing simulations of snow cover during melt.;In general, the model performed well until the onset of melt. Thereafter the model greatly over-predicted melt rates. There were also problems with melt water transfers in the snow cover which will need to be addressed in future versions of the model. Improvements will also need to be made to the routines handling vapour transfers in the snowpack and snow density calculations. However, with these modifications the model shows some promise to become a useful model for simulation of spatial and temporal variations in snow cover properties.;Keywords: Snow depth, Snow density profile, Snow Melt, Snow Cover mapping, Landsat image, Mass and Energy Balance, Geographic Information System (GIS).