陕北及鄂尔多斯地区降水变化与沙漠化

本文根据1959～1984年降水记录,讨论了陕北及鄂尔多斯地区沙漠化和草场退化的主要原因.由于沙漠化范围扩展阶段与降水量减少阶段的影响范围具有一致性,所以认为主要原因是自然过程。因1980年以来本区降水出现增加趋势,本区自然环境向沙漠化的发展将受到抑制。

PRECIPITATION CHANGE AND DESERTIFICATION IN THE REGION OF NORTHERN SHAANXI AND ORDOS

It is demonstrated that recent drought is the factor more importent than the activities of humanbeings that bring about the desertification in the re- gion of Northern Shaanxi and Ordos. The study of the precipitation change from 1959 to 1984 in this area show that the expanding of desert in this area is associated with the drought tendency. Along with the trend of deser- tification, there are changes of other components of physical environment, such as the deteriorating of grassland, the decreasing of runoff and sand dis- charges, and the shrinking of the lakes. The interchanges of desertification and nondesertification, loess deposition and formation of paleosol, farming and stock raising that happened in the prehistoric age and the early stage of history in this region, further proved that it is the climatic change and not the human activities which is the most important factor that induced the change of environment in this region.