Multi-level Optimization Of The Landuse In Developed Counties

China has entered a rapid development period of up to thirty years since its reform and opening up. With the development of economic and social transformation,the land resource's scarce, inefficient use, configure unscientific influence on the economic and social sustainable development will be more and more severe. In developed areas of China which are the pioneers of regional developments, land use problems are more outstanding. Studies have shown that the lack of land resources, the imbalance of regional economic development,the security of grain and the degradation of environment spatial inequalities of regional development, food security risks, environmental pollutions and the stagnation of the ecological environment are the four main challenges in developed areas. In order to solve contradiction between human and land in economically developed areas to achieve the region's economic and social sustainable development, it is need to strengthen the research on developed areas of land resources configuration issues. Those researches can help to solve the critical land use problems such as the spatial disorder of land use,the number of land use structure is not reasonable, the mode of development extension and expansion and the county land resources scale single in economically developed areas. It is also have some references to economically underdeveloped areas about the land use. In addition, the county level is the smallest spatial unit in metropolis developments and it's also the basic administrative division in China for social management with complete authority for land resources management.Hence, the study of optimal allocation of land resources in developed counties in China is of great importance.Yixing City, belonging to Wuxi City, Jiangsu Province, is the country's top ten economic country; since 2011, the city's per capita GDP more than $ 10,000;the industrial structure of the city is 4.5: 55.5:40. The city's highest economic density is the central and northern of the taiga plain, followed by the Northeast Area, the lowest density are the low-lying western towns and hilly southern towns. Yixing's GDP per kilometer square construction land is more than 250 million yuan, and its rural construction land per capita is more than 150 m2;the ability of economical and intensive land have to improve. Besides, the per capita arable land area of Yixing in 2011 is only 0.74 acres, which is already below the security cordon of 0.8 acres proposed by FAO. Last but not the least, studies have shown that the improper economic development and land utilization in Yixing induced many ecological and environmental problems, such as the blue algae bloom in Taihu. Overall, the economic and social development of Yixing City is in a high level, but the transition problem such as the development of the inside area is very uneven,the red land security and ecological environment problem has been showing ,the type of land use is an extensive type , the regional division of labor is not obvious and the development of towns are convergence ,allocation of land resources is not reasonable ,is very prominent,which is the right choice to carry out the study.Utilization of land resources emphasizes its spatiality. There are different issues at different scales; its need to focus on their own problems to resolve. On existing land resources of county configuration optimization research, or stop at the county level, the feasibility and the pertinence are not strong; or different scales use the same method, the system and complementarity are not strong. The discussion about a particular spatial scales is more, but how to meet each other and interface each other between different scales of space optimization mode only have little research. The existing methods often determine the optimal allocation strategies of the county's land resources, but all types of land quota allocation between towns are not optimal. So, if you cannot control indicators and optimize the number of various types of land on the township level or layout the various types directly to the plot scale rather than village scale; in the actual land resources management, it is difficult to be well implemented. Therefore, in the study of the county's land resources, it is necessary to give full consideration on the target of county, town and village levels different actors decomposition and mutual coupling. Therefore, based on the existing research, our research build an economically developed areas' "County - Town - Village" on Land Resource Allocation Optimization theoretical system which is based on human-land coordination theory, comparative advantage theory, system theory and scientific theory,balancing urban and rural theory. Our research also propose a land use classification system which is based on the dominant features perspective to study spatial and temporal difference and change tendency of the regional's land-use. Furthermore , our research complete the regional land resources tertiary scale systematic optimal configuration by county scale's land-use main function zoning macro guidance, township scale's land use structure optimization medium control, village scale's land use patterns adjust specific microscopic realization.Main conclusions of the case study of Yixing City which research on its land resources optimize by different scales are listed as below:(1) The way" county level's partition boot - town level's structure optimization - village level's model realize" these three levels to implement and coordination division scale division of the county's land resources can break main transition problems of land use in the process of economically developed counties' development in some extent. The zoning at county level is actually a macroscopic guidance for organizing spatial land utilizations and regional productions; the structure optimization at town level is mainly a microscopic control of the spatial-temporal distribution of all the land use types so as to implement the macroscopic guidance for different towns; the mode-based land use readjustment at village level is a microscopic implement of the land use structure optimization goals of certain towns in a practical way.(2) The spatial-temporal differences of Yixing's land use between 2000 to 2011 are very significant. Areas of land mainly for living use increased stably while areas of land mainly for production use continued to decline. Functional structure of regional land use became more balanced, with the relative dominance of production and ecology weakened gradually.Yicheng District, Economic Developing Zone (EDZ) and Industrial Zone of Environmental Science and Technology (IZEST) are the settling-suitable centers of Yixing most suitable for settling, while the south hilly regions and ecological venerable regions around the Ge Lake are least suitable for settling. The production function dominated regions usually locate at suburbs of the settling-suitable centers of Yixing, influenced mainly by economic developments. The ecological function dominated regions usually locate at out suburbs of the settling-suitable centers of Yixing including the south hilly regions and ecological venerable regions around the Ge Lake and Taihu,influenced mainly by regional natural conditions. The overall livability of Yixing's land use system enhanced year by year, but still doesn't match its economic development level, its living function and logistics function remain to be further enhanced; the growth of living land and traffic land remains the main trends in transition, mainly use the existing urban developing core (Yicheng streets,development zones and Central Park Branch) as the center and predominance-area to spreading outward.(3) Land utilization zoning at county level based on the quantitative SWOT analysis showes that: EDZ, IZEST and Guanlin Town belong to the land use key development zone;Xinjian Town, Gaocheng Town, Heqiao Town and Gaotie Town belong to the land use expansion zone. Yangxiang Town, Xushe Town, Xichu Town, Zhangchu Town, Dingshu Town, Wanshi Town, Fangqiao Town and Xinzhuang District belong to the land use appropriate development zone; Taihua Town, Hufu Town and Yicheng District belong to the land use optimized development zone; and 5 ecological important regions (Taihu Region, Ge Lake Region,The Yixing Forest Farm, The Daxianling Forest Farm and Hengshan Reservoir Region) belong to the land use restrictive development zone. We further come up with different policies according to the economic-societal development levels and their land use status quo. Correspondingly, we suggest different population policies, industrial policies,investment policies and fiscal policies to better implement the land use strategies of each zone.(4) Based on scenario-based forecasting and gray multi-objective dynamic programming, an empirical study which the end of the study period is 2020 of key development zone - Guanlin Town in Yixing City showed that the area of its village construction land should decline to 200.94 hm2 from 1524.55 hm2, and the water body area should decline to 3598.74 hm2 from 3751.91 hm2. Besides, more land for mining and industry should be consolidated, and more unutilized land should be made of full use. Thus the area of Guanlin Town's transportation land should increase from 508.84 hm2to 1037.96 hm2, the area of its cultivated land should increase from 3325.08hm2 to 3678.40 hm2, the area of its urban construction land should increase from 1317.92hm2to 1651.36 hm2, the area of its forest land should increase from 21.93hm2to 175.10 hm2, the area of its garden land should increase from 14.08hm2to 164.90 hm2. Although Guanlin Town's grassland and attached production land need no numeral readjustment, they should be rearranged spatially to promote their land use efficacy. After the optimization of Guanlin Town's land use structure,its economic output will increase by 0.17 percent, its ecological output will increase by 0.29 percent, while its societal benefit will decrease by 1.05 percent.(5) Based on the improved gravity model, the social combustion theory, the four-quadrant analysis model and the entity-relationship model, the land use change and readjustment mode analysis at village level of the 18 villages in Guanlin Town shows that Guanlin Village, Binhu Village and Lidu Village are a low-risk village for urban type land use adjustment which applicable for nearby urbanization mode; Lingxia Village and Dushan Village are a high-risk village for urban type land use adjustment which applicable for special urbanization mode; Daru Village, Yizhuang Village, Shaoxiang Village, Gehu Village and Dongyao Village are a low-risk village for countryside type land use adjustment which applicable for taking the new industrialization mode; Fengyi Village, Nanzhuang Village,Yangshe Village,Baimang Village,Niujia Village, Gezhuang Village,Guifang Village and Qiancheng Village are a high-risk village for countryside type land use adjustment which applicable for taking the agricultural modernization mode. The modes which are used to adjust the villages' land use differs from each other in terms of their target problems,application conditions and solutions. And the difference in solutions is the key content,including the main land types to be readjusted,policies relied on and relocated person's arrangement and so on.