Study On The Optimization Of Urban Spatial Structure In Huangling City Based On Ecological Security

Huangling County is located in the ecologically sensitive Loess Plateau ravine area in northern Shaanxi Province,and is affected by topography,soil quality and climatic precipitation,which means that the city faces serious soil erosion,weak water conservation capacity and frequent geological flooding.At the same time,the development of Huangling County is also constrained by the external natural ecological environment,and there is a shortage of land resources available for urban development and construction,resulting in the spatial structure of the county facing problems such as the development of urban construction breaking through the natural ecological constraints,the fragmentation of the county’s internal landscape and ecological space,the disproportionate and loosely organised functional structure,and the inefficient and ineffective transportation network.In Huangling County,it is important to coordinate the relationship between urban spatial development and the natural ecosystem,define the ecological bottom line,anchor the ecological base,and optimize the spatial structure of the county for sustainable spatial development.This paper takes an ecological security perspective and takes Huangling County,a typical belt-shaped city in northern Shaanxi,as the research object.The first part is the analysis of the research foundation,which consists of the research background,the definition of the research object and concept,the current situation of domestic and foreign research,the research purpose and significance,and the research method and technical route.Through a review of domestic and international literature,it is determined that the spatial structure optimisation of Huangling County is mainly carried out from two aspects:the spatial structure base is the blue-green network of Huangling County,and the spatial structure base is the functional structure and transportation system.The second part is the interpretation of the spatial structure characteristics of Huangling County from the perspective of ecological security and the analysis of the problems.After reviewing the basic overview of Huangling County,the spatial evolution and construction of Huangling County,the spatial structure of Huangling County is analysed in a qualitative and quantitative manner,and the problems of the spatial structure of Huangling County are analysed as follows: the spatial development of the city breaks through the external ecological constraints and threatens the ecological security of the county,the total amount of internal green space is insufficient and spatially fragmented,the functional structure of the county is out of balance and fails to highlight the ecological pattern,the land use of the county is unbalanced and does not match the natural ecological pattern.imbalance in land use and poor connection with the natural ecological environment,disorganised internal and external traffic,poor axial connectivity,and lack of and unsystematic slow-moving systemsThe third part is the construction of an ecological safety pattern and the optimisation and adaptation of spatial structure from the perspective of ecological safety.Firstly,the construction of an ecological safety pattern.Based on the ecological dilemmas faced by Huangling County and the natural ecological resources it possesses,this paper uses the technical path of "ecological source site identification-ecological corridor extraction-ecological safety pattern construction" to construct an ecological sensitivity assessment and ecological service importance assessment to identify Important ecological sources are identified and ecological corridors are extracted on the basis of the minimum cumulative resistance surface.The ecological source sites,ecological corridors and ecological safety levels are superimposed to build the ecological safety pattern of Huangling.Secondly,the spatial structure of the county is optimised according to the ecological safety pattern.For the spatial structure substrate,there are three main aspects of the optimisation study.The first is to analyse the spatial structure of the spatial substrate of Huangling County and the ecological security conflict,and the second is to determine the substrate organisation pattern of Huangling County through relevant literature research,and then to clarify the substrate optimisation elements as mountain green areas for stability and protection,river systems for linkage and connectivity,and ecological patches for recreation and leisure.The final proposal is a three-dimensional,pearl-shaped,three-dimensional substrate organisation model with "a single vein running through the city,seven hills protecting the city,eight centres and multiple corridors,and a mosaic of groups".The spatial structure of the base is adapted in three main ways.The first is to analyse the conflicts between the spatial structure and ecological safety of Huangling County,the second is to clarify the ideas of optimising the spatial structure,and the last is to adapt the spatial structure of Huangling County from two levels: the functional structure and the traffic system.At the level of functional structure,after analysing the factors influencing the functional structure,the development orientation and functional composition of Huangling County City are clarified,and through the rational layout of each functional zone,the intensive use of land and the synergistic development of clusters are achieved.In terms of the transport system,the transport system of the county is optimised at three levels: external transport relief,internal transport system organisation and ecological slow-moving system connection.This paper attempts to explore the spatial structure of Huangling County from the perspective of ecological safety through the optimal adaptation of the spatial structure of the base and base surface of Huangling County,with a view to providing reference for the construction and development of other small cities in the gully area of the Loess Plateau in northern Shaanxi.