Delimitation Of Urban Growth Boundaries Based On The Ecosystem Service Value

Since the reform and opening up,the rapid expansion of urban space had led to a huge decline in agricultural land and ecological land,which resulting in the weakening and degradation of ecosystem service functions and severely affecting the regional ecosystem balance.At the same time,the urban master planning which guides the development of the city mainly focuses on the allocation of construction land and space resources,ignoring the connotation of urban ecosystem service functions that resulting in a lack of effective guidance for the improvement of the living environment.With the further advancement of the national ecological civilization reform,how to guide the orderly development of cities,ensure ecological security and improve the value of ecosystem services has become an important way to implement the ecological civilization strategy.Taking the Hengyang central area as an example,this paper analyzes the change of the land use and the assessment of ecosystem service value from 2000 to 2010.Then the importance index of various ecosystem service functions based on the dynamic change of ecosystem service value coupled different types of habitat quality indexes into the minimum resistance model to construct a regional ecological security pattern,and then delimit the rigid growth boundary of the city.With the prediction of the urban population and the scale of urban construction land in 2030,the boundary of urban elastic growth in 2030 is delineated by coupling the urban ecological security pattern and the results of urban expansion simulation based on the FLUS model.The results shows that:(1)From 2000 to 2010,the area of construction land and water increased by 3,520.26 hm~2,26.36 hm~2 respectively;while the area of cultivated land,forest land,grassland and unused land decreased by2227.63 hm~2,13.804.02 hm~2,103.05 hm~2,and 16.92 hm~2,respectively.(2)From 2000 to 2010,the total ecosystem service values in Hengyang's central area decreased from 2.575 billion yuan to 2.547 billion yuan.The value of hydrological regulation and water supply service functions was increasing,while the value of other ecosystem services is decreasing.Hydrological regulation and climate regulation served important regional ecosystem services;food production,water supply,gas regulation,soil conservation,and ecological diversity served major regional ecosystem services;raw material production,purification of the environment,maintenance of nutrient cycling,and aesthetic landscape Servd functions of regionally important ecosystems.(3)The Hengyang central area can be divided into three levels of low,medium,and high levels of ecological security pattern,with the areas of19893.06 hm~2,24054.39hm~2 and 7485.57 hm~2 respectively.The urban rigid growth boundary was delineated on the basis of the low ecological security pattern area,with an area of 19975.77hm~2,and accounting for 38.84%of the total area.The urban rigid growth boundary is distributed along the two sides of the Xiang River,Zhengshui Water and Leishui Water,forming a"three corridors and three slices"space structure,which plays an extremely important role in the natural ecological protection and ecosystem services of Hengyang central area.Development and construction of the bottom line area.(4)After considering the restricted development conditions of ecosystem service functions,the ecological cost of urban expansion is reduced,the total regional ecosystem service value is increased,and regional ecological security is guaranteed.In 2030,the area of the urban elastic growth boundary will be 20074.59hm~2,accounting for 39.03%of the total area of the study area.Its spatial form will be distributed as"one central area,multiple groups".Zhengxiang District,Shigu District,and Yanfeng District will form a large-scale and relatively continuous growth boundary,while the growth boundary of Zhuhui District will relatively scattere and the scope will be relatively small.Based on the delineation results of the urban growth boundary,the urban spatial pattern of“two hearts,three corridors,and five districts”in the central urban area of Hengyang will be initially established.(5)In the future,we should pay attention to the relationship between man and land,innovate the management system of man and land.use the land intensively on the basis of building a reasonable ecological red line,and strictly control the development sequence of urban construction land.At the same time,in the process of implementing the urban growth boundary,we should clarify its legal status,coordinate with the multi regulations,and encourage the public participation,so that it can better enhance the capacity for sustainable development of urban space and the flexibility and enforcement effectiveness of urban growth boundary space regulation.The proposed method and results can scientifically evaluate the ecological cost of urban expansion and effectively resolve the contradiction between urban development and ecological protection,which can also provide an important basis for urban master planning,ecological protection planning and optimization of national territory development planning.