Research CA-Markov Model Based On The Loess Plateau And Temporal Carrying Capacity Of Land Use Change

With population growth and rapid economic development, human use of land resources continue to strengthen in the breadth and depth, resulting in shortage of resources, environmental pollution and ecological destruction and other issues, and this largely affects the modernization process, becoming the bottleneck of sustainable development. Since the1980s, the international scientific community has organized the implementation of the World Climate Research Programme, the International Geosphere-Biosphere Programme, the International Human Dimensions Programme on Global Environmental Change and the International Biodiversity Programme, etc. global Environmental change Research Program, in order to comprehensively study the Earth system and its changes on the global sustainable development. Among these land use change is the main reason for global environmental change and an important part of. Land use change not only for regional ecosystem structure, composition and function have an important impact, but also have a strong effect on economic development. Therefore, land-use change research becomes the focus of international research. The analysis of regional land use, and land-use trends simulation for improving the structure and pattern of land use, maintenance of agricultural land and water resources balance, exploration of regional water resources sustainable utilization mode, has important theoretical and practical significance.Cellular automata (CA) model is powerful for spatial operations. It can effectively simulate the spatial variation of the system. Markov model uses the state transition probability matrix to predict the evolutionary trends of this system. CA-Markov model combines the space changing ability to simulate complex system of CA model and the long-term prediction advantages of Markov, can not only improve the prediction precision of the transformation of land use types, and can effectively simulate the space changing of land use structure and has great scientificalness and practical applicability.This research applied RS and GIS technology, taking two periods remote sensing images of2000year and2010year as key spacial data resources, and used some materials, including land use status, land use planning, and regional social economy information as attribute data resource, to establish the database. It analysed the land use characteristics of spatial and temporal dynamic changes since the policy of returning cultivated land to forest (grassland) was implemented in North Shaanxi Loess Plateau and predicted the land use change trend of this district in2020and2030on the basis of CA-Markov model.In this research, some important results have been concluded:(1) The spatio-temporal dynamic changes of land use is significant.①The amount of farmland area has decreased as a whole, for reasons including ecological restoration, the implementation of the policy that soil planting is according to its quality situation; farmland occupation, owing to infrastructure construction in the process of urbanization.②The amount of garden plot has increased in the mass, for fruit industries of good economic benefit are encouraged to develop after agriculture restructuring, which indicates the transformation of farmers’ income source from the only food production to integrated development of agriculture, forestry, animal husbandry and sideline.③The amount of forested land, bush forestland and grassland has increased in the mass, which is mainly distributed in water conservation forest such as Ziwuling, Laoshan and Huanglongshan in the southernern Yan’an, and sand-fixing forest along the Greatwall in the northern Yulin.④Construction land is one of the lands, area of which changes fastest. The increase of traffic land makes a major contribution.⑤The water area has increased slightly, mainly because many projects are built in the process of Exploitation and utilization, increasing the water storage area, such as reservoirs, main dams, warping dams, irrigation engineering and so on.(2) The increase of population and decrease of farmland resource have brought serious regional man-land contradictions. In the year of2010,14of25districts and counties of the Loess Plateau in northern Shaaxi were overloaded, accounting for25percent;8of them were in a population-grain balance; only3counties were surplus areas. The research predicted that in the year of2020and2030, respectively, there would be15and16overloaded counties,7and6balanced counties, and both merely3surplus areas. Accordingly, without considering the impact of human activities, including, mountain cutting, valley filling and new town construction, etc, the population carrying capacity of land resources in the Loess Plateau in northern Shaaxi would decline.(3) The preservation of farmland resource, promotion of population quality, the implement of energy and ecological compensation mechanism is the key to assure regional grain safety and land ecology security. The concrete policies are as follows:①Insist on protecting land resources and assure grain safety.②Develop the population scale in a reasonable way, and improve the ratio of high-quality population.③Perfect the eco-compensation mechanism to exploit and utilize cultivated land resource sustainably.④Establish mineral energy resource compensation policy for availing and protecting to secure regional land ecology safety.The feature of this research is the combination of CA model able to simulate the spatial-temporal evolution of complex system, and Markov model, having an advantage in long-term prediction. It stimulated the land use change trend of Loess Plateau in northern Shaanxi, and organically integrated the district land resource quantitative proportion and spatial distribution. Besides, it stimulated the spatial temporal tendency of Loess Plateau’s land resource carrying capacity in northern Shaanxi at a county scale, based on the prediction of land use change and regional population development, with the evaluation model of national standard, the’Technical Guidelines of State Population and Development Function Division’.The study provided the scientific references in the coordination of regional land resource balance and the sustainable exploitation.