Research On The Organization Mode And Pattern Optimization Of Green Space In The Typical Cold Island Area In The East Of Jinan City Center

With the continuous advancement of rapid urbanization,cities are faced with many environmental and climate problems,such as the overall temperature rise,the intensification of air pollutants,and the increase of extreme weather,which seriously affect the quality of urban human settlement environment.Among them,the urban heat island effect is the most significant and far-reaching climate problem.As an important public resource that is fair,shared and green,urban green space is the infrastructure and important carrier of providing many services such as temperature and humidity regulation and pollutant regulation.The service quality of urban green space directly affects the physical and mental health and well-being of urban residents.In order to maintain the public health of urban residents and achieve sustainable urban development,it is urgent to alleviate the urban heat island effect.The research on the cooling effect and cooling efficiency of urban green space provides a new breakthrough for the current urban development and future green space planning.On the basis of summarizing the current research on urban heat island effect and the theoretical progress of cold island cooling mechanism,this study first proposes the criterion of urban cold island region.Combined with the relevant research results of local climate zones,this study identifies the typical cold island region dominated by urban green space in the eastern part of Jinan City Center in the summer,and preliminarily screens the urban green space that has spatial correlation with the typical cold island region.Secondly,the change point method of isotherm perimeter-temperature curve in the existing research results is optimized,and the cooling efficiency of urban green space is represented by the normalization of cooling range and cooling range.Meanwhile,the cooling efficiency of spatially related urban green space in the typical cold island region is measured to screen the urban green space with high cooling efficiency in the typical cold island region.On this basis,the organization pattern of urban green space with high cooling efficiency is summarized under the support of landscape pattern index at three scales of patch,class and landscape.Finally,with the support of CFD software modeling and simulation,the convention and exhibition center block is selected as a typical block.According to the organization pattern of urban green space with high cooling efficiency,the urban green space optimization scheme is proposed,and the urban wind and heat environment before and after the green space optimization are compared and analyzed.Based on the simulation results,the structure optimization strategy of urban green space in the eastern part of Jinan City Center is proposed from three scales of patch,class and landscape,in order to provide theoretical basis and methodical support for the improvement and perfection of urban green space system planning guided by high cooling efficiency.Based on the above research analysis,the main results and conclusions of this study in terms of the organization pattern of urban green space with high cooling efficiency and the structure optimization of urban green space in the eastern part of Jinan City Center are as follows:(1)At the patch scale,the spatial morphology of green patches with high cooling efficiency is within a fixed value range in AREA,PERIM,GYRATE,CIRCLE,SHAPE,FRAC,PARA,CONTIG.At the class scale,the combination of green space with high cooling efficiency forms a structural composition with park green space as the center,land for squares as the auxiliary,protective greenbelt as the supplement,attached green space as the foil,and regional green space as the characteristic.At the landscape scale,the green space combination with high cooling efficiency has an organization pattern in which dominant patch is prominent,the average size of patches is moderate,the shape of patches is regular,the degree of separation of patches is low,the degree of physical connection of patches is high,all types of green space are evenly distributed,and the landscape richness of all types of green space is high.(2)According to the structure optimization of urban green space in the eastern part of Jinan City Center,control the green space area,break it up into parts,and adjust green space shape to reduce the complexity at the patch scale.Adjust green space structure,change "fit in a hole" to "efficient organization",and protect the existing mountain green space to show the urban characteristics at the class scale.Uniform allocation of various types of urban green space to improve the diversity of green space,and build urban green corridors to enhance green space connectivity at the landscape scale.