| Studies on environmental vulnerability is one of the key fields of the study of global environment change. At present, there have been few studies on Degree and Process of environmental vulnerability and few case studies. No model has been established that is accurate and can be generally accepted. Since middle time of the twentieth, social and economic activities of human result in that the vulnerability of environmental change strikingly reinforce, human society and ecological environment are more vulnerable than before. And environmental degeneration, climate change and activities of human have more notable effect on vulnerable or transitional areas of ecological environment.Mu Us Desert is a very typical vulnerable ecological area and transitional area and it is influenced profoundly by human activities. To great degree, it represents many typical problems in the relationships between human activities and natural environment in semi-arid and arid desert regions of China. It has great significance to carry out the research on environmental change, regional response and man-made influence of the region, especially to desertification control of agriculture and animal husbandry interlaced area in northern China, to ecological environmental construction of China and to regional development striding across provinces or districts.Under the background of global change, how does Mu Us Desert respond to that? How does the environment change? To what degree do human activities influence it? What are the quantitative relationships between man-made factors and environmental vulnerable change especially desertification? On the basis of research theories and methods of environmental vulnerability, by using the software such as Excel, Maplnfo, Photoshop and mathematical statistics, the characteristics of environmental vulnerability change of Mu Us Desert is analyzed, vulnerable degree assessment model is established, environmental vulnerable degree is evaluated and man-made influence in the process of environmental vulnerable change is discussed. By analysis and research, the following significant conclusions are drawn:1. The climate of Mu Us Desert has distinct warming and drying trend: the precipitation has decrease trend in recent 50 years and it reduces 1.4137 millimetersannually on the average and the coefficient of variation is 0.2341; The temperature has increase trend and it rises 0.0265 centigrade annually on the average and the coefficient of variation is 0.0785. The change of temperature has taken on increase trend from the middle of 1950's to 1990's; The change of precipitation and temperature both take on the quality of fluctuation and stages and regional difference is also obvious.2. The shortage of water is very serious and water-reducing trend is evident in Mu Us Desert: the precipitation can't meet the need of dry agriculture; the runoff decreased gradually even cut off; the level of under-ground water decreased in large range. The whole vegetation coverage is low and variation of regional coverage is large. Partial vegetation coverage increased to some extent, man-made destroy and creatures' destroy were serious, population reduced acutely and biodiversity decreased gradually. There exist many disadvantageous meteorological calamities, the frequency of drought, torrential rain, frost, hail, blown-sand disaster and so on is high, the intensity is large, they last long and have developing trend.3. The fluctuation of agriculture production and economic development are large, the proportion of agriculture is large and economic development depends on farming to great degree and the vulnerability of economy is large: cereal crops occupies high proportion in crops; total output of cereal is unsteady evidently and output per capita is low, they have increase trend slightly; cultivated land area totally and per capita reduces in large range; the proportion of farming, forestry, animal husbandry, side-line and fishery is excessively large, estate structure is monotonous, agricultural develop...
|
PDF Full Text Request