Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
Wang Ling, Wang Qinxue, Zhang Ruyi
The influence of human activities on environment and climate is the most conspicuous problem of the Loess Plateau, and it may be divided into two aspects:First, the excessive utilization of land by human race causes the destruction of vegetation, and consequently large expance of land is under desertification and the characteristics of the ground surface and the water and heat excha'nge on the ground surface are changed.Second, the use of coal by industries produces a huge amount of carfoondioxde and trace elements, which enter into the atomosphere and cause air pollution.Data of 1951-1990 are collected from 69 meteorological stations on the Loess Plateau. After analysis, the decadal variaions of temperature and rainfall in the last 40 years are obtained.1.In the arid zone of the northwestern of the Loess Plateau, the increase in temperature is the largest. For the past 40 years, the annual mean temperature has increased 0.7-10℃. In the semiarid zone of the middle part of the Plateau, the annual mean temperature increases 0.1-0.5℃, while in the subhumid zone of the southern part, the temperature remains almost constant and even has a slight decrease.2.For the past 40 years, the large and middle-sized cities have the largest temperature increase, especially the industrial cities of the modern type.3.For the past 40 years, the rainfall has decreased in the most part of the Loess Plateau.
