Eco-space And Ecological Land Use Distribution Of Urban Agglomeration

Urban agglomeration is a product of population aggregation and social development.It is a combination of various cities in the region.It is a complex of economy,nature and society.It is the growth pole of regional economy and the spatial carrier of national urbanization.Our country will build more than 20 city groups of various sizes.Ecological lands have ecological service functions such as maintaining water and soil,conserving water areas,and beautifying the environment,which can protect the ecological environment of the urban agglomeration and maintain the balance of the regional ecosystem.In order to explore the relationship between the development of urban agglomerations and the distribution of ecological land,the following studies have been made in this paper:First,from the three aspects of nature,economy,and society,a set of indicators system for evaluating ecological cities was constructed,including a total of 28 indicators.Based on the principle of principal component analysis,the core cities of the region were screened out;using the revised gravitational model and field strength model,the method of defining the scope of urban community ecological space was formulated.Research shows that the core city of Beijing-Tianjin-Hebei urban agglomeration is Beijing;its ecological space scope includes: Beijing,Tianjin,Baoding,Shijiazhuang,Langfang,Tangshan,Chengde,Zhangjiakou and Changzhou.Secondly,through the single land use dynamic degree model and the comprehensive land use dynamic degree model,the change of ecological land use in the ecological space range of Beijing-Tianjin-Hebei urban agglomeration during 2009-2016 was analyzed,and the ecosystem service value of different lands in the area was calculated during the eight years.The research shows that:(1)In 2009-2016,the dynamics of regional farmland,forest land,grassland,water wetlands,and construction land were-0.058%,-0.076,-0.22%,-0.733%,-0.237%,and 1.277%,respectively.The area of regional ecological land is decreasing year by year,while the area of construction land is increasing year by year,with an increase of 302.5 square kilometers;(2)The ecosystem services valueof the eurban agglomerations co-regional regional also changed with the change of land use types,from 1193.716 billion yuan in 2009 to 1166.326 billion yuan in 2016.The ecosystem services value of the state system in each city area has been decreasing.Tangshan and Beijing have seen a greater reduction,reaching 6.959 billion yuan and 4.104 billion yuan respectively.The impact of construction land on the ecosystem is increasing;(3)The value of various types of services in different land types is also decreasing year by year.Finally,based on the landscape pattern of "plaque-corridor-matrix" in landscape ecology and the optimal landscape pattern theory of "combination of concentration and decentralization",the distribution of ecological land use in each municipality was analyzed,and the distribution pattern of each city was changed.Analyze the causes and propose reasonable and feasible control measures.(1)The distribution of construction land in Beijing is too concentrated,there are few small patches of green corridors and ecological land in built-up areas,and the distribution of land types is unreasonable;(2)The coastal cities of Tianjin,Tangshan and Quzhou are driven by the foreign economy and ports,and there is little distribution of ecological land in the coastal zone during the period of 2005-2015,and construction land has changed significantly;(3)Langfang was affected by the radiation of Beijing and Tianjin.The ecological land was divided by the construction land and the fragmentation was serious.(4)The ecological land in Chengde and Zhangjiakou has a wide area and reasonable distribution,which is in accordance with the planned urban agglomeration ecological conservation area;(5)The distribution of ecological land in Baoding has changed little,while the construction land in Shijiazhuang has gradually expanded and extended.In the development of urban agglomerations,it is necessary to regulate the distribution of regional ecological land from the aspects of policies,planning and laws,protect the regional ecological red line,and improve the ecological environment quality of urban agglomerations.