1996 Volume 58 Issue 4 Pages 303-316
The effect of snow cover on the heat balance of the ground surface in north-western China is investigated with a heat-water balance model. (1) The calculated snow accumulating and melting processes are in close agreement with the routine observations. Significant correlation is found between the maximum snow water equivalent (or the last day of snow) and the integrated heat fluxes for the long period from snow melting season to early summer. (2) The ground surface temperature begins to rise just after the snow desappearance. Consequently the sensible and latent heat fluxes increase abruptly from a negative value to a positive one. The water content in the top soil layer increases for about 10 days due to the melt water, then the water content decreases to a small value, so that the sensible heat flux becomes small. (3) In arid and semi-arid regions, a greater part of rain water is lost by evaporation within a few days after the rainfall, so the water resources becomes very little. At a region with snow cover in winter, however, a considerable amount of melt water formed in the spring makes a contribution to the water resources.
