Dynamic Simulation And Prediction Of Xi ’an Urban And Rural Construction Land Change

The land use pattern change from the state of nature to the state of human life and production is the inevitable result of human and natural interactions. Rapid urbanization has become a common phenomenon in the global scope, especially in developing countries. As the biggest developing country, C hina has experienced a dramatic and rapid economic change in recent years, and the city scale is expanding rapidly. The urbanization process of China presents distinct characteristic s such as too fast, regional differences, mak ing great changes in land use pattern, and then led to a massive loss of farmland, water resources scarcity, environmental pollution, ecological pressure of energy resources and environmental problems. In order to scientific balance the pace of urban development and the ecological environment security, it is necessary to realize scientific and rational urban land allocation of resources, and control the scale of the development of the city and urban land use structure and intensity. This set even higher requirements and challenges to the optimization of urban land use structure and strength. So studying the urban expansion drive mechanism and predicting the future trend of urban land use change has important significance for improving land use efficiency, realizing the sustainable development of cities and the environment. Along with the advancement of urbanization, land use change driving mechanism analysis and simulation has become a focus of research scholars in China and abroad. To present the measures of construction and land change researches is not comprehensive, single time and space scales, obsolete data, et al. Xi’an as the largest city in northwest China, is in the process of building an international metropolis. It is typical to speed up the pace to the geographical expansion of cities in recent years. This article is in the funding of Shaanxi province natural fund "Xi’an landscape patt ern change ecological effect research", and it is based on four land use status data of Xi ’an in the year of 1975, 1900, 2000,2010 and 2015, combined with the natural and social economic indicators by using Arc GIS10.1, SPSS22, IDRISI17.0 software. It is analysis Xi’an from three regional scales such as whole, urban and rural and district, by using the area, density, the urban construction land expansion intensity index to measure the depth and breadth of Xi ’an construction band change rule and its driving mechanism. It simulates the change trend of construction land of Xi ’an in 2020 and 2025 by using the CA-Markov simulation.The results show that:(1) In recent 40 years, the area of land construction in Xi’an city expands from 81787.30 ha in 1975 to 119570.31 ha in 2015. High density construction land increases significantly and center city, urban and rural construction land are moving to the direction of high density and intensive use pattern. The growth in center cities and towns is significant. In the process of urbanization, the trend of Xi’an city presents multi-center expansion, high land. There is an obvious double center in Gaoling, Lintong and Hu country. While the center of Yanliang, Lantian country are around administrative center expansion.(2) Growth of the Xi’an construction land is mainly affected by the terrain, wetlands, traffic, the town center. When multiple driving factors interact, highway plays the most significant role in promoting the geographical expansion of cities, and slope factor has obvious limitation to it. In the natural factors, the influence of wetland is the largest in Xi’an urban sprawl. Xi’an is located in the northwest inland, and it is drought, water shortage. It is a typical inland city. With the development of the soc iety and the expansion of cities, urban issues are becoming increasingly complex. The wetland has become one of the important reference factors, when urban population chose to live. This impels the wetland to become a driving force for construction land expansion. Among the social and economic factors, the influence of highway on Xi’an construction land growth is the largest. Xi’an is the capital of Shaanxi province. The road network is dense, convenient, powerfully promoted the expansion of the city, mak ing the Xi’an city area has greatly increased.(3) Combined with the CA model and Markov model, it forecast Xi’an future development trend of the construction land in the future. The results show that after 2015, Xi’an construction land sustained rapid growth. It is expected to reach 166181 ha in 2020. The growth rate is more than 2010-2015.After 2020, as the urban scale tends to be more stable and mature, relevant policy guidance for the protection of ecological security, the speed of construction land gro wth is slowed significantly. It is expected to reach 174999.33 ha in 2025.(4) The growth of the construction area is mainly derived from the conversion of cultivated land and a small amount of forest land and wetland. In order to ensure the stability of the ecological environment and food security, Xi’an construction should attach great importance to the construction of urban ecological security. The protection of forests and wetlands. And also should strengthen the protection of historical and cultural sites in the future. Promoting the sustainable development of urban and rural construction should be based on urban ecological civilization, regional ecological security and food security.