Study On The Spatial Structure Optimization Of Longdong Small Valley Cities From The Perspective Of Ecological Restoration

Longdong is a typical loess plateau area.The small Valley Cities formed in this area naturally face the problems of land resource shortage,high ecological sensitivity,and difficulty in reconciling urban construction and ecological environment.With the rapid expansion of the Longdong small Valley Cities,the urban ecological environment is deteriorating day by day,and the resource and environmental carrying capacity has been greatly weakened.In order to rebuild the balance between the artificial environment and the natural environment,ecological restoration and urban spatial structure optimization are urgently needed.The optimization of spatial structure is one of the important ways to achieve ecological restoration.The concepts and methods of ecological restoration can guide the optimization of spatial structure,so it is particularly necessary to explore how to optimize the spatial structure from the perspective of ecological restoration.This study explores the mutual feedback mechanism of ecological restoration and urban spatial structure on the basis of expanding the ecological restoration connotation and combing the relevant research of urban spatial structure,and determines the optimization content of urban spatial structure from the perspective of ecological restoration as ecological network,urban growth boundary,road system and core system.Based on the diagnosis and evaluation of the spatial structure optimization content of the Longdong small Valley Cities,and under the guidance of the ecological restoration concepts and methods,the problem-oriented and "firstto-last-draw" ideas are used to construct the Longdong small Valley Cities spatial structure optimization framework and optimization technology.In terms of ecological network,the ecological sensitivity assessment is used to identify important ecological patches,the biological resistance corridor is constructed with the least resistance model,and the catchment corridor is constructed based on the simulation of the catchment and the fractal characteristics of the water system of the small city of Longdong small Valley Cities,Corridor integrated into a crossconnected ecological network.In terms of urban growth boundaries,rigid urban growth boundaries are delineated with GIS-based core ecological space overlays to protect important ecological spaces from encroachment;GIS-based land growth simulations are used to delineate flexible urban growth boundaries and guide urban compact ecological development.In terms of the road system,based on the analysis results of the spatial syntactic line model,the overall planning road network structure and road grade are optimized.In terms of the core system,the spatial syntax line segment model is used to analyze whether the overall planning central system is established,whether the central system determined by the overall planning is reasonable,and whether the urban spatial potential is fully utilized.The overall planning road network model constructed in GIS is used to determine the core Whether the system service capacity is reasonable,based on which the central system is optimized.Finally,taking Huanxian County as an example,the effectiveness of the spatial structure optimization framework and optimization technology of Longdongchuan-type small cities was verified.In this paper,through the combination of qualitative and quantitative methods,the spatial structure optimization framework and optimization technology of Longdong small Valley Cities are constructed from the perspective of ecological restoration,with a view to expanding the content of ecological restoration and enriching the content of spatial structure optimization.Planning provides reference.