关键词: 城市绿地, 斑块, 应急避险功能, 空间格局, 评价

Abstract: Based on the remote sensing data and population data of Beijing from 2005 to 2020, with the support of RS and GIS technology, we analyzed the changes of landscape pattern of urban green space and its emergency evacuation ability in different periods using the landscape pattern metrics. The results showed that the total area of urban green space in Beijing increased gradually from 2005 to 2020, with a higher growth rate from 2010 to 2015. The area of park green space showed similar characteristics. The auxiliary green space and protective green space showed a trend of increasing first and then decreasing, while the area of production green space presented a gradually decreasing trend. From 2005 to 2020, the large-scale green space patches with an area of larger than 50 hm² increased annually, which was conductive to emergency evacuation. From the perspective of spatial distribution, the nearest neighbor index of green patches in 2005, 2010, 2015 and 2020 all exceeded 1.5, and the spatial distribution of patches was relatively uniform. However, large green space patches (larger than 50 hm²) were mainly distributed in the central and northwest parts of Beijing, with less distribution in the southern part of Beijing, which should be comprehensively considered in the later planning and construction process of urban green space. In 2020, the population density in the core urban area was relatively large, and population density gradually decreased from the inside to the periphery. The population density in the southwest and northeast regions was relatively low. According to the service radius of 500 m, the coverage of green buffer zone in Beijing urban area in 2020 was 1076.36 km², accounting for 96.6% of total urban area, with only 38.06 km² service blind area, which was mainly distributed in the core urban area. Under the service radius of 1000 m, the service blind area was only 0.59 km², indicating a full coverage.

Key words: landscape pattern, evaluation