摘要
城市植被是缓解城市热岛效应的重要因素,但对于城市林地斑块冷岛效应沿城乡梯度变化的分析鲜见报道。本研究选定上海作为研究区域,基于遥感影像,通过土地利用类型提取和地表温度反演,以城市发展水平不同区域表征城乡梯度,以各区内林地斑块为对象,对其冷岛效应的变化及其与林地斑块特征关系进行分析。结果表明:上海市林地斑块有明显的冷岛效应,整体上,林地斑块地表温度比上海市平均地表温度低0.55℃;在中心城区,其冷岛效应最为显著,降温幅度可达1.67℃,而在远郊区,林地斑块不再具有冷岛效应;在各城市发展水平区域,林地斑块面积和形状特征均对冷岛效应有显著影响,林地斑块越大、形状越规则,则冷岛效应越显著;反之,冷岛效应则渐趋减弱;随着城市化程度升高,面积更小、形状更不规则的林地斑块能发挥一定的冷岛效应。本研究结果可为今后制定城市内差异化的生态建设提供科学依据。
Vegetation is a key factor to mitigate the urban heat island effect because it can form the local cool island.Previous studies focused on the local cooling effect of vegetation and water bodies in urbanized regions.However,few studies have figured out whether such effect would vary along the urban-rural gradient,as well as the relationship between such variations and the geometry characteristics of urban forest patches.In this study,we first retrieved the land surface temperature(LST) and the land use from Landsat 8 TIRS and GF-2 PMS imagery,respectively,and then analyzed the cooling effects of urban forest patches in Shanghai via buffer analysis method.Different urban development zones with various urbanization levels were used to represent the urban-rural gradient.Results showed that LST of the urban forest patches was 0.55 ℃ lower than the mean LST in Shanghai,indicating the role of forest patches as cool island in urban thermal environment during the daytime in summer.However,such effect of forest patches was not consistent along the urban-rural gradient.Strong cooling island effect was found for those in the downtown,with a reduction of LST up to 1.67 ℃.Forest patches did not serve as the cool island in the outskirt,such as in Chongming District.In each region,the area and shape characteristics of forest patches exerted great influences on the cool island effect.The patches with large size and regular shape had stronger cool island effect compared with those with small size and irregular shape.Compared to those in the region with low urbanization level,the small and irregular shape forest patches in the region with high urbanization level were apt to serve as cool islands.These findings can provide scientific support for future urban greening and ecological construction.
作者
仇宽彪
张慧
高吉喜
裴文明
张彪
王敏
王卿
QIU Kuan-biao;ZHANG Hui;GAO Ji-xi;PEI Wen-ming;ZHANG Biao;WANG Min;WANG Qing(Nanjing Institute of Environmental Sciences,Ministry of Ecologyand Environment,Nanjing 210042,China;Jiangsu Collaborative Innouation Center of Atmos-pheric Environment and Equipment Technology,Nanjing University of lnformation Science&Tech-nology,Nanjing 210044,China;Ministry of Ecology and Enwironmental Center for SatelliteApplication on Ecology and Enuironment,Beijing 100094,China;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Shanghai Municipal Bureau of Ecology and Enwironment,Shanghai 200003,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第5期1409-1418,共10页
Chinese Journal of Ecology
基金
国家重点研发项目(2017YFC0506600)
上海市环保公益科研项目
2020年中央部门预算事业费项目资助。
关键词
城市热岛
降温幅度
城市化
城市森林
热环境
urban heat island
cooling amplitude
urbanization
urban forest
thermal environment
