THEORETICAL STUDY OF COLD-AIR DRAINAGE

The formation and characteristics of cold-air drainage are studied in this paper. The terrain is con-sidered as an ideal two-dimensional slope which is infinitely extended in y-direction. In general situations,the regularity of cold-air drainage in temporal and spatial variations is obtained by solving numerically theatmospheric equations of motion, the continuity equation, the thermodynamic equation, the surface thermalbalance equation and the soil heat conduction equation. We also test the changes of cold-air drainage withcloudiness, the coefficient of turbulent exchange, slope and its length, and the heat flux and thermal charac-teristics of soil. The calculated results are in agreement with observations.