Proper Scale Of Qiemo Oasis In Xinjiang And Its Sustainable Development

For the study of Oasis expansion on the imaging law of fragile eco-environment in arid area, this study selected water resources, climate, vegetation, soil, topography as the key environmental elements of desert oasis. Qiemo oasis with a representative for the study area, using a combination of macro and micro, qualitative and quantitative and 3S (RS, GIS, GPS) technology, on-site surveys and other technical means of combining research methods, to overcome the single-factor analysis and its direct alignment restrictions, from a holistic, systemic perspective angle, the size of the arid area oasis with key environmental factors of the evolution and its mutual relationship are analyzed. It has made a little research results in these aspects that the scope of expansion of Oasis in the arid region and sustainable development of regional eco-environment system.1.Comprehensive considering the socio-economic and ecological environmental characteristics Qiemo oasis, combined with the data sources of field data and remote sensing image information, and through the Delphi method, firstly established three categories of 23 kinds of the evaluation index system concluded geospatial subsystem, human and social subsystems and economic development subsystem of oasis scale expansion. Through the correlation coefficient matrix analysis, the study selects 16 indicators closed to the expansion of the oasis scale from the 23 indicators influenced the expansion of oasis scale. Using 53 years data in 1957-2009, principal component analysis and though the analysis of large amounts of data, the 16 indicators are further divided into three main components. The second principal component of climate factors (evaporation) is the most relevant to the area of oasis and reflects the climate factors on the influence of the oasis scale expansion is the most significant. Due to climate dry, less precipitation, high temperatures, strong evaporation, leading to water shortages; these directly make impact on the oasis scale expansion. Other major factors also have per capita grain and cultivated land area, reflects that driven by population growth and socio-economic development, expansion of oasis area caused by the increased cultivated land area, thereby further affect the stability of the oasis.2.Oasis is mainly human activity sites in arid areas. The scale of oasis directly impact on the water resources carrying capacity, stability and economic development of oasis. Conversely, too-rapid economic development on the natural resources of high-strength taken would influence the oasis scale. The study uses four different periods of remote sensing image data in 1970,1990,2000 and 2009 year of Che'erchen the middle and downstream plain oasis. It used ENVI4.7 software for interpretation, classification and statistical processing. According to the vegetation coverage, the study divides the study target area into oasis, ecotone, water and desert four different landscapes (separation of 1.857~1.995), analyze the dynamic change trend for nearly 40 years of Qiemo Oasis.The results show that: the whole oasis is in the expansion trend over the years. From 1970 to 1990, the oasis area increased 19.54% from 2.46%, ecotone area decreased from 22.19% to 6.15%, but changes in water and the desert is not too large. From 1990 to 2000 Oasis area reduced to 7.02% from 19.54%, ecotone area increased to 12.94% from 6.15%, the area of water reduced and the area of the desert expanded. From 2000 to 2009, the desert area from 76.56% down to 70.73%, the area of ecotone and Oasis has increased.At the same time, land use types are divided into arable land, woodland, grassland, water area and unused land. The results show that: on the side of land use, area of cultivated land from 1970-2009 has been showed an increasing trend, the proportion of it has increased to 1.09% in 2009 from 0.43% in 1970, area has increased 91.29 km~2, average annual increased 2.34km~2, dynamic degree is 3.93%, is the largest growth scope in various land use types. One of the fastest growing is 2000-2009; cultivated land area increased 56.49 km~2 during 9 years, average annual increase of 6.28km~2, dynamic degree is 6.64%. Little changes appear in other types of land.The changes appeared from the research area fully explain human activities and natural factors on the response of the surrounding environment. Due to water shortage, salinity, desertification and other natural factors, and the livestock population surge driven by economic interests. Not only reduce the pasture area, but also the quality is in a sharp decline. Therefore, population growth and economic development is the direct driving force.3.Established that are subject to evaluation index system of water resources carrying capacity in arid area. By using the fuzzy comprehensive evaluation method and multi-level fuzzy comprehensive evaluation model, the study analyzed the water resources carrying capacity of Che'erchen River basin. The comprehensive evaluation results of water resources carrying capacity of Che'erchen River is deviation, v3 and v4 respectively are 0.2581 and 0.2458. In order to further study on water resources carrying capacity, according to the appropriate ecological water requirement in research methods, the study calculated ecological water demand of Qiemo Oasis is 3.014×108m3, but the available water of Qiemo Oasis is 3.2708×108m3, so ecological water demand of the total 92% of available water. This shows the amount of water of Qiemo Oasis is almost all used for ecological water. It further verify the result that the deviation of water resources carrying capacity.If you expand the size of oasis, you will increase the burden on water resources. The scale of arid plain oasis should be determined by the water. To prevent land desertification and desertification caused by over-exploitation on the condition of water shortage, the study presents the concept of proper scale of oasis, chooses the best model for computing proper scale of oasis, and takes the empirical analysis combined with the actual situation of Qiemo Oasis.Proper scale of oasis is comprehensive considered the natural environment conditions and social needs of oasis. It is assumed that the limited surface water and specific temporal and spatial distribution and existing canal system utilization factor and other input conditions can maintain a relatively stable theoretically and could be used to develop and utilize by human. Though the empirical analysis of proper scale model of oasis, finding that water and heat balance method model is the best model for computing proper scale of Qiemo Oasis. Study obtained that the stability index of Qiemo oasis is 0.5358, so the oasis is in the second stable state, the ecological system starts to degenerate, so oasis requires a higher input to stable. Qiemo oasis proper scale is 609.22～812.29 km~2,Qiemo oasis proper cultivated area is 92.66～123.55 km~2. Through the data shows the existing scale of Qiemo oasis is 992.16 km~2,which is beyond Qiemo oasis proper scale 0.2～0.6 times. The existing of cultivated area is 150.88 km~2,which is also beyond proper cultivated area 0.2～0.6 times. From the perspective of ecological sustainability, oasis area is unfavorable to expand.4.According to water - ecological - economic and social analysis of the interaction between coupled systems of Qiemo Oasis and discussion about the the coupled system of sustainable development model, through the Delphi method, the study established the sustainable development evaluation index and the standard value appropriated to water resources in arid oasis area; using the fuzzy optimization model make multiple evaluation index into a single index; using evaluation methods described complex water resources system for sustainable development; combined with the actual situation of development and utilization of Qiemo Oasis water resources; studied the relationship between the sustainable use of water resources and the coordinative development of economic and social and proposed the corresponding control measures.The results show that: nearly 10 years the characteristic value of indicators of sustainable development of Qiemo Oasis water resources system is in an average between grade 3 and 4. Sustainable use of water level is still relatively low, the exploitation of water resources is not reasonable and the relatively low overall level. Facing the actual situation of Qiemo Oasis, the study proposes control measures for sustainable development of Qiemo Oasis as follows: proper handling of the economic and ecological water ratio between water, correctly deal with the relationship between the origins and main stream, correctly handle the relationship between surface water and groundwater, properly tackle the relationship of artificial oasis with the natural oasis, properly handle the relationship between exploitation of resource and water, properly handle the relationship between construction and the unified management, adjust the structure of oasis agricultural planting, develop water industry, control of population growth, improve population quality, reduce pressure on resources and the environment.