Study On Urban Park Green Space System Planning Based On GIS And Spatial Syntax ——Taking The Central District Of Lanzhou City As An Example

Urban park green space system is the subsystem of urban green space system,and also the core factor of sustainable,renewable and recyclable development of modern city.Scientific and rational urban spatial structure is the key to the park green space ecological function into full play,the landscape pattern related to the space syntax theory to the urban park green space layout to conduct a comprehensive analysis and research,help to comprehensive,scientific and accurate understanding of city park green space construction level,for the construction of city park green space system to provide the theoretical basis and reference,Give full play to the ecological service function of urban park green space.Supported by GIS technology and spatial syntax analysis method,this thesis takes lanzhou city center as the research target,carries out visual analysis and interpretation of remote sensing image of Lanzhou city center in 2021,and obtains the schematic diagram of urban park green space classification information,so as to establish lanzhou city center park green space information database.Through quantitative analysis of landscape pattern and space syntax model based on GIS,this thesis puts forward the existing problems and optimization strategies for the spatial layout of lanzhou downtown urban park green space,and builds and plans the lanzhou downtown urban park green space system scheme on this basis.The findings include:1.Study on landscape pattern of parkland in central City of Lanzhou:The total landscape area of Lanzhou city park green space is 1038.77hm2,accounting for5.51%of the total land area of lanzhou city center,which is relatively small in the urban park green space system and fails to give full play to the best ecological benefit function.（1）At the level of patch type,the patches of integrated park green space were large in area,wide in distribution and large in quantity in the whole park green space landscape,and the number and density of patches were 85 and 0.1282/hm2,respectively.The percentage of patch type in landscape area was the lowest,which was 6.94%.The patch density,average patch area and percentage index of patch area to landscape type were 0.3114 patches/hm2,3.22hm2 and 22.64%,respectively,but the quantity distribution was very scarce.The patch density of community park green space was large,but the patch area and average patch area index were the smallest,which were 73.89hm2 and 1.42hm2,respectively,indicating that the patches were strongly disturbed by human activities,leading to high degree of landscape fragmentation and poor connectivity.The number of small patches was large,but the area index of the largest patches was the smallest（97 patches,9.89%）,indicating a high degree of landscape fragmentation.（2）At the level of landscape types:Lanzhou downtown urban park green space types are complete,but the landscape fragmentation degree is high and the connectivity is poor.Xigu District park green space patch landscape fragmentation degree is the highest,5.52·km^-2.The number and area of urban park landscape varies greatly among different types,but the overall spatial layout in a certain region has a high degree of agglomeration and integrity,and the aggregation index of the four districts is above 90%.2.A study on the syntax of parkland space in lanzhou City center:Combined with lanzhou image map,overall urban planning map and the actual situation of field investigation,the axis model of lanzhou downtown area space syntax is drawn by auto-CAD,and its variable index is calculated by related software.The analysis results show that:（1）In terms of integration degree of park green space:there are few parks in central urban area of Lanzhou,most of which are distributed in the west of Chengguan District and the east of Qilihe District with high integration degree,as well as along the banks of the Yellow River.In this area,the road carrying capacity is high,the flow of people is large,the park green space layout here has a high degree of travel,and the connection with the surrounding environment is good.（2）In terms of the permeability and accessibility of park green space:the central location of Lanzhou and the surrounding areas along the waterfront of the Yellow River have strong permeability and accessibility of park green space.In this area,the road network structure is perfect,the population is large,the connection degree between the entrance and exit of the park green space and the surrounding environment is high,and the global and local accessibility is good.The overall planning and construction of Xigu district and western Anning District is slow,the traffic network is not convenient,and the permeability and accessibility of the green space of the park in this region are relatively weak.3.Planning scheme of Lanzhou city Park green Space SystemBased on the landscape pattern and space syntactic analysis of urban park green space in lanzhou city center,and according to landscape ecology and landscape pattern optimization theory,the urban park green space system planning scheme of"one heart,two corridors,two belts,three groups,four axes and multiple parks distribution"was proposed.It solves the low coverage rate of urban park green space and the unbalanced and uncoordinated layout of park green space in the city,and further creates the landscape pattern of urban park green space integrated with landscape pattern.