Evaluation Of Urban Agriculture Ecological Security In Xi'an Metropolitan Area Under Urbanization

Urbanization and industrialization promote the development of the social and economic, and also brought a series of ecological problems and caused a certain impact and destruction of human life, and even seriously threaten the survival of human, the hot topic of multidisciplinary and multi-field research has been caused by the reason of ecological security. Urban agriculture is located in the inner city and its extension area,"service city, relying on the city", and it is effected deeply by urban development, With the development of urbanization and industrialization, the large-scale population agglomeration, that leads to urban large scale, diversification of market demand for agriculture, and combine with city staff, technical and economic support; therefore, these promote the rapid development of urban agriculture and its internal structure transition and upgrade quickly. Due to the urban agriculture is located in the inner cities and its extension area, So it is the forefront of agriculture and vulnerable to be effected by urban development, environmental damage, the influence of the production and living of pollutants.Urban economic development, the periodic fluctuations of the market itself will cause the production scale, product structure and the severe changes of economic benefit etc. so urban agriculture belongs to the ecological vulnerability of agriculture. These make the sustainability and system stability of urban agriculture ecosystem productivity of urban agriculture suffer hard-hit, and show the significant vulnerability, the ecological security is facing a great threat. In this paper, based on the TM remote sensing image data, social and economic statistical data, by means of RS, GIS and SPSS and Vensim software platform, analyzes the space-time evolution and the change of the ecological security of xi’an metropolitan circle urban agriculture ecological security, as well as the2000,2005and2011; Finally, the paper divides the degree of xi’an city circle urban agriculture ecological security and predict ecological security of xi’an metropolitan circle urban agriculture.This study aimed to provide a new train of thought for xi’an metropolitan circle urban agriculture ecological security research, to some extent, expansion of GIS application in agriculture; it is fulfilling the research content of urban agriculture to make a small contribution and offers some reference to strengthen the construction of realizing international metropolis in Xi’an, it provide theoretical basis for the ecological environment governance and urban agriculture resources protection, and provide reference for xi’an coordination between urban and rural areas, the future city development and the economic development and planning of guanzhong tianshui economic zone.Through the research and analysis, drawing the following conclusions:Firstly, the ecological security of Xi’an metropolitan circle urban agriculture were gradually improved from0.388to0.551in Xi’an city since the years of2000. Xi’an metropolitan circle implement energy conservation and emissions reduction of agriculture, urban agriculture ecological environment has improved continuously, and strengthen the agricultural non-point source pollution control and reduce agricultural wasting of the ecological environment; and also enhance agricultural science and technology innovation ability improve the urban agriculture ecological security index.Secondly, urban agriculture ecological security situation in xi’an metropolis circle present obvious spatial differentiation characteristics, which is that city ecological security composite index is lower than the surrounding area, population urbanization leads to the reducing of agricultural land,urban agriculture is facing the greater the pressure on land resources, the population urbanization make the lack of per capita water resources as well as the ecological security index reduce important aspect; In present, urban agriculture ecological security situation presents good trend gradually from north to south, the southern region ecological environment condition is better, rich natural resources, and the government increasing the development of modern urban agriculture the qinling effect in the north of QinLing is the main reason.Thirdly, from2000to2011, the urban agriculture ecological security of xi’an metropolis circle is that the better area is more than the worse.Improvement areas are mainly concentrated in north qinling region, mainly is the natural resource advantages, and with the convenient of the round-the-mountain roads in qinling, the establishment of the agricultural science and technology demonstration park, agricultural tourism sector, ecological safety improve; Downtown area and XianYang area, the main causes of ecological security deterioration is the urban agriculture of cultivated land resources shortage because of urbanization, population urbanization leads to increase in the number of population, decrease per capita water resources and break production and living pollution damage to the ecological environment, etc. which make the urban agriculture ecological security situation did not be better, but worse.Fourthly,The degree of Xi’an metropolitan circle overall status:the level of urban agriculture population security from the core region of city circle to the surrounding areas is reinforcement; Resource advantage of resource security is mainly affected by itself and the influence of building international metropolis,The resource safety in LianHu district, BeiLin district,new district, yanta district, BaQiao district of core region in Xi’an decreaser; However, The resource security in LanTian county, Weitang district,Lintong district is on the rise; Environmental security is closely related to urbanization development level, the core metropolitan areas such as Xincheng district, Beilin district,Lianhu district urban, agriculture environmental security level has been low; in close distance core such as Yanta district, Baqiao district, Weicheng district,which environmental safety has dropped; The rest of the county and district’s agriculture environment safe level basic no change; Social security and economic development is closely related to the regional economic development and resource quantity, the regional economic development lags behind, the urban agriculture social and economic development level is relatively low, such as LiQuan county, JingYang county; The social economy development of the shortage of natural resources is relatively backward, such as the core metropolitan areas.Fifthly, the forecast analysis of Xi’an metropolitan urban agriculture:advancing with time, the total urban agriculture ecological security index rose, in2020was0.58,2030was0.60,2040was0.63,2050was0.70; From the point of ecological safety hierarchy, by2050, the state of ecological security level has been from the "safer" into a "safe" state.