Study Of Driving Factors Of Desertification In Mu Us Sandland

Desertification called"earth cancer"is the most severe disaster which mankind face in many ecology and environment problems at present. Therefore, the study of desertification is gradually payed double close attention and becoming hot spot of study. Mu Us sandland which is the important barrier shield of China is very important to social economy and ecological environment.Mu Us sandland was one of the most important city in history, and the record of desertification is only thousands of years. There is no agreement among many views a-bout the reasons of the desertification, so the sandland is the model which is about interaction of human factors and natural factors. In the paper, we analysis mainly the process and driving factors of desertification, and predict climate, arable area, and number of livestocks in the future by establishing mathmetic equation and illuminate the drive factors. At last, we point out direction for development of agriculture and paturing in Mu Us sandland.Main contents and results of study as following:1. In human historic period, from the end of the Tang Dynasty to the Qing Dynasty, fluctuation of desertification was mainly due to climate factors and human activities which include estrepement, overgrazing and cutting trees and grass, furthermore, the place was the base of military which caused fights often taking place and soil was held up. From the Qing Dynasty to the republic to building up a station, the cause of desertification was mainly that more population aggravated cultivating land, overgrazing and cutting trees and grass. From the end of the Tang Dynasty to the Qing Dynasty, the rule of desertification of Mu Us sandland is similar to that of some large deserts and sandlands in north of China. From the Qing Dynasty to the republic to building up a station, not only Mu Us sandland,but also the whole world are desertifying, so Mu Us sandland is not artificial sandland.2. From 70 era to 80 era 20th century, climate happened evident change and developed to good direction. Annual mean temperature heightened, which displayed warm winter and warm spring. The change of annual precipitation and annual mean temperature has been displayed synchronism. Day number of gale and evaporation lowered year by year. The change is fitted to growth of vegetation and recovery of ecosystem. Climate of southeast area obviously is superior to the northwest area. In southeast area annual mean temperature is higher, and precipitation is richer, as well as day number of gale is fewer, which show warm and wet. On the contrary, in northwest area climate shows cold and dry. Water duty of all sections of national economy increases significantly. In last 10 yaers, industrial water increased about 10 times, and agricultural water also increases too much. Water duty has been increasing too much, so that the human affairs about waters are frequent. Capacity of surface water and water of passing through the territory take on reduced tendency in different era. The amount of farmland irrigation water is 85% among all national economic departments. At present supply and requirement of water volume is fundamental balanced. Water resource gradually reduces from southeast area to northwest area in Mu Us sandland. The amount of arable land and livestocks gradually increased by population pressure and policy targeting from 50 era to 70 era 20th century. After 80 era 20th century, arable land and livestocks amount gradually decreased because nation practiced system for contracted responsibility to family united production. In 90 era 20th century, arable land and livestocks amount gradually increased for satisfying to people requirement of living material. Since 1998, arable land and livestocks amount gradually decreased accompanying practice of national engineering on returning cultivate land and return land to forest and grassland.3. Natural factors and human factors display coupling in the process of desertification in Mu Us sandland. According to principal component analysis, natural factors are main resulted factors, and human factors make acceleratory effect.4. Development direction of agriculture and pasturing are: first, developing water saving agriculture; second, practicing protection measure to cultivation, such as minimum tillage and no-tillage system; third, practicing prohibiting grazing in grassland, developing pasturing in agriculture area, practicing grassland construction in the area which is not fit for agriculture cultivate in order to construct a bit of land for protecting a flood of land.