The Study Of Oasis Proper Size Based On The Oasis Self-organization And Hetero Organization Principle

Oasis is the concentration of human and social wealth in arid area, and it is also an important material foundation for social and economic development in this area. Due to it is in the background of large area of desert, the oasis area climate is very drought, the vegetation is sparse, the water resources are scarce, and the ecosystem is relatively weak. In recent years, with the continuous growth of the population and the continuous development of social economy in arid areas, and the development of oasis resources continues to increase, the scale of the evolution of the oasis has also been a certain degree of disturbance. Because of the influence of different human activities, the evolution of the oasis scale presents two kinds of different trends of the oasis development(expansion) and desertification(shrinking). Rational exploitation and utilization of oasis resources can realize the rapid development of the local social economy under the premise of ensuring the sustainable development of the oasis system; exploiting the oasis resources blindly will destroy the stability of the oasis system, which will lead to some problems of social economy and ecological environment.Keriya Oasis is located in the southern margin of the Tarim Basin in Xinjiang Uygur Autonomous Region of China, and it is a very typical ecological fragile area. In the national preferential policy support, nearly 30 years since the local economic and social development has made great progress. However, with the continuous expansion of population size and the over exploitation of the resources of the oasis, the change of the scale of the oasis and the destruction of the ecological environment has been caused. How to rationally utilize the local natural resources and to control the scale of the oasis in a reasonable range has become the key to realize the sustainable development of human and nature. Firstly, this article uses the RS technology to extract and analyze the change of Keriya Oasis scale from 1995 to 2010. Secondly, use the information entropy method to study the development situation of the social economic system. At the same time, apply the principal component analysis method to calculate the induced rate of the contribution of the different factors that influence the changes of scale of Keriya Oasis, and extract the main driving factors of oasis scale evolution. In addition, from the perspective of the human and the nature harmonious development, establish the oasis scale suitability evaluation index system, and based on the statistical data of Keriya County from 1980 to 2010, calculate the coordination degree index of economic, social and ecological environment three subgroups. Finally, it makes a comprehensive evaluation on the suitability of different periods of Keriya Oasis scale. The main results of the study are the following four aspects:1. By 1995, 2000, 2005 and 2010 four remote sensing image classification results of Keriya Oasis shows, from 1995 to 2010 in Keriya Oasis the grassland, water area showed obvious decreasing trend. Therefore, although the area of cultivated land has been expanded in this period, the area of oasis and the interlaced zone are reduced.2. According to the current situation of sustainable development of social economic system in this period, from 1980 to 2010 in Keriya Oasis the entropy generation, entropy flow and the total entropy of the social and economic system present the condition of fluctuation, but on the whole it is in a downward trend. This shows that the development of the social economic system in Keriya Oasis is stable, and the system is developing towards the direction of relative order. However, from 2004 to 2010, the total entropy of the social economic system showed an upward trend, reflecting the local social and economic development in this period has been a certain limit.3. On the basis of the comprehensive analysis of the Keriya Oasis, the driving factors which affect the scale change of the oasis are extracted by the method of principal component analysis based on the data acquired. The results show that in 1980 to 2010, the main driving force in the evolution of the size of Keriya Oasis is human impact factors. In the human impact factors, the total population, scale of agricultural production and the resident income level are main factors of influence in Keriya Oasis scale change. In the natural influence factors, the contribution of air temperature and precipitation to the change of oasis scale is the largest.4. Through the processing and operation of each index data of the Keriya Oasis scale suitability evaluation, it is concluded that in the same session Keriya Oasis economic, social and ecological environment of the three subsystems benefit index as well as the coordination degree among these three subsystems, and according to this the scale suitability of Keriya Oasis in different years was evaluated. According to the calculation results show that, from 1980 to 2010 in Keriya Oasis economic benefit index and social benefit index shows a rising trend, and ecological environment benefit index appears fluctuation state. The change of Keriya Oasis scale appropriate degree can be roughly divided into three stages: In the 1980 s Keriya Oasis economic, social and ecological environment three subsystems coordination degree index is relatively high, and the development of the oasis scale is appropriate; In the 1990 s, the coordination index of the three subsystems was decreased compared to the former stage, and the development of oasis scale transformed into relatively suitable; From 2000 to 2010, the coordination degree index of the three subsystems was in the lowest level of the three periods, and the appropriateness of the oasis scale also transformed into appropriate and inappropriate since 2003.