Study On The Change Of Blue-Green Space In Different Cities In Hunan Province

Rapid urbanization has brought the expansion of urban space,it also brings environmental degradation,urban congestion and other issues.In recent years,people's attention has been paid to the blue sky and green space in the city.At the same time,the application streetscape big data technologies provide a new path and closer to the people of this city of blue-green perspective for space research.In this paper,the administrative center of Changsha,Hunan Province,three districts(Furong District,Kaifu District,Tianxin),13 the next nine county-level cities and prefecture-level cities,a total of 25 different levels of the city for the study.In this paper,urban street scene images are used as data to analyze the changes of urban blue-green spatial differences.The main research contents and results are as follows.(1)Using OSM road network data as basic data,combined with web crawler technology to access Baidu map and Tencent map to obtain city street view image data.Based on the machine learning algorithm,the blue sky and green plant elements in the street view image were identified and their proportions were calculated,and the blue space,green space,and blue-green space ratios of each study area were obtained.(2)This article finds that the county has the most blue spaces,and the prefecture-level cities have the most green spaces and blue-green spaces.County-level cities have the largest difference between blue space and green space,and the gap between provincial cities and prefecture-level cities in blue-green areas is relatively small.At the same time,this paper explores and studies the distribution pattern of blue space,green space and blue-green space in regional cities,and summarizes it into four types: uniform distribution type,strip change type,center divergence type,and clump distribution type.(3)This article finds that in different areas of the same city,the blue-green area of the city is closely related to the population density of the area,the per capita GDP of the residents and the housing prices of the city.And in the three administrative regions of Changsha,prefecture-level cities and county towns present different correlations.(4)Comprehensive analysis of urban blue and green space development issues,adhering to the principle of people-oriented,from an ecological perspective.This article separately puts forward suggestions on optimizing transportation and green planning for the construction of the blue-green space of the provincial capital city Changsha;proposes localized measures for the construction of the blue-green space of prefecture-level cities;and proposes to increase the application of information planning technology for the construction of the blue-green space of county-level cities.This paper makes up for the current gaps in related research in the central and western regions,provides low-cost,large-data new feasible methods for urban data collection,and provides a new perspective for urban spatial evaluation and planning.The research in this paper also provides a solid and reliable scientific basis for achieving sustainable development goals and building an ecological livable city.In the future,we will further explore the research on improving the accuracy of relevant models and the three-dimensional blue-green space of cities.