Quantitative Analysis on Driving Role of Human Activity on the Land Desertification in Arid Area: The Case of Tarim River Basin

Land desertification is one of the most prominent ecological and environment problems in arid area. The reasons of it occurring and developing especially distinguishing of natural and human factors are problems which researchers in this field devoted to solve. In this paper, taking the typical arid area-Tarim River Basin as an example, main influence factors of land desertification were analyzed. The 4 important roles of human activities in desertification were given: the increasing population will initiate and aggravate land desertification; human development causes cultivated land activity and provokes the land desertification; the advancing techniques reduce consumption of natural resources and increases income and thus inhibit desertification; policies and management can aggravate and inhibit desertification. On the base of this and the authors' past research work, 15 indices included natural and human factors were selected, 7 statistical indices of reflecting human activities variables (population, population density, cultivated land, grain crops, per capita out of grain, number of domestic animals, animals capacity of cultivated land) and 8 observed indices of natural variables which concluded climate (precipitation and temperature) and hydrology (water supplies of source streams in 6 hydrological stations). A calculation method of quantitative human driving role in the land desertification were designed by using factor analysis (FA).Human driving force on land desertification in this river were discussed using this method. And the researching period were divided into 2 periods:1949～2000 and 1985～2000. The results show that human driving force on land desertification was accounted for 75% in 1949～2000 and for 69% in 1985～2000. This indicates that technique advance and management can weaken the negative effect of human activities.