Numerical Simulation. The Greening Of China's Western Region, Desertification, Climate Impacts Research

By using NCC-T63 coupled with land-surface process model, sensitivity experiments of desertification or virescence grass over the west part of China are implemented to study the effect of vegetation type on the climate. Results show that precipitation and surface temperature will be changed obviously when the vegetation type over the west part of China is changed. In summer, when the desert over the west part of China is replaced by short grass, surface temperature of replaced region will reduce, precipitation of most part of the northern and the western China will increase, especially from the east of Tibetan Plateau to Northern China, along the spreading path of southwest monsoon; when the vegetation over the west part of China is replaced by desert, surface temperature of replaced region will increase, precipitation of most of China will decrease except the east and the south part of Tibetan Plateau and east littoral. In winter, when vegetation type over the west of China is changed, the region of surface temperature changed is large, and the variation of surface temperature is complicated, the variation of precipitation is mostly in middle and east part of China. Changing the surface vegetation type will change the surface albedo -. the surface roughness and other underlying earth抯 surface parameter, and will also change soil texture-~ soil color~ initial soil moisture content, then it will change absorption of ground to solar radiation, change long-wave radiationN sensible heat flux and latent heat flux between land surface and atmosphere. Because cold and heat source is the power of driving and maintaining monsoon operation, the variation of ground heat source will change the monsoon circulation, therefore change climate. This experiment suggests the afforestation and virescence in western part of China will improve the climate condition in most of our country.