EVOLUTION TENDENCY OF PLAEOCLIMATIC ENVIRONMENT IN THE WEST LOESS PLATEAU SINCE THE LATE PLEISTOCENE
黄土高原西部地区晚更新世以来古气候环境的演变趋势

Based on a great deal of the data from C14 dating measurement and analyses of sporo-pollen combinations, this paper dealt with the evolution tendency of palaeoclimatic environment in the west loess plaleau since the late plaistocene. It was found that in the area north of the line going from Lanzhou through the southern Jingyuan to Huanxian County,the semi-arid climatic environment under the modern steppe and the desert steppe might have been created basically since the late pleistocene and it is drier at present than ever before. However, in the stepped land south of the Yellow River at Lanzhou before about 7600 years back from now, it might be in a semi-humid climatic environment. In the area south of the same line as aboue, the semi-humid climatic environment under the modern forest-grasslands and grasslands might have been gradually created only for the late 7400 years. Before then,the plaeoclimate in most of mountain region of the same area might be more humid than at present.This finding may be considered as a scientific basis for the conservation and development of natural resources in the areas studied.