绿洲-荒漠交界处蒸发与地表热量平衡分析

本文利用波文比方法对绿洲－荒漠交界处的绿洲和荒漠的蒸发和地表热量平衡过程进行了探讨．结果表明，波文比方法对于绿洲适用而于荒漠却不适用．

ANALYSIS OF LAND SURFACE EVAPORATION AND HEAT BALANCE IN THE TRANSITIONAL ZONE OF OASIS-DESERT

Oasis and desert are the two completely different landscapes. The study on the water and heat courses in the transitional zone of oasis-dcscrt is concerned with many scholars all along. In this paper, the sensible and latent heat fluxes are calculated and analyzed with Bowen ratio-energy balance method. In desert, the sensible beat nux calculated with Bowen ratio-energy balance method is greatcr than the heat supplied by land surface, in the meantime, atmospheric latent heat is transported down. It is impossible tliat there are so great evaporation and latent heat on thc arid land surface of desert and that the latent heat is transported down in high temperature season. It is obvious that Bowen ratio-energy balance method is available in oases and invalid in deserts.Through the analysis to oases, it is show that: (1) Evaportranspiration from hanland (such as cotton, rice and wheat fields) in growth season is greater than the evaporation from water surface. (2) The maximum daily evaporation from farmland appears at noon or a little later, and decreases toward the two sides on the evaporation curve. (3) Through the analysis to every component of Rn-G=H+LE, tbe following conclusions can be obtained: Oases are the great vapour sources, and in a certain degree they can be regarded as the latent heat flux collectors.