A Simulation Study on Climatic Effects of Land Cover Change in China

The regional climate model RegCM4 was used to investigate the regional climate effects of land cover change over China. Two 24-year simulations (1978-2001), one with the land cover derived from the MODIS data and the other with the CLCV (Chinese land cover derived from vegetation map) data, were conducted for a region encompassing China. The difierences between the MODIS and CLCV data re?ect characteristics of desertification and degradation of vegetation in China. Results indicate that the land cover change has important impacts on local climate through mechanisms related to changes in surface energy, water budgets and macro-scale circulation. In summer, the land cover change leads to a decrease in surface air temperature over southern China, a reduction in precipitation and an increase in surface air temperature in the transitional climate zone and the northern Tibetan Plateau, and an increase in inter-annual variability of surface air temperature in the marginal monsoon zone and northwestern China. Strengthened southwesterly winds increase precipitation to some extent in central and eastern Inner Mongolia by enhancing water vapor transport. In winter, enhanced northerly winds, bringing more dry and cold air, lead to a reduction in precipitation and temperature over areas south of the Yellow River.