北京地区热岛非均匀分布特征的卫星遥感-地面观测综合变分分析

Integrated Analysis on Unsymmetrical Space Distribution Characteristics of Urban Heat Island Based on Variational Processing Method in Beijing

针对北京城市热岛的空间变化特征及其发展趋势,重点探讨了北京城市热岛总体演变趋势及其多尺度非均匀分布特征与城市建筑群面积、中高层建筑群空间布局的相关关系。采用晴空过程北京城郊地面自动气象站AWS(Automatic weather station)气温观测真值对卫星遥感云顶黑体温度TBB(Temperature of black body on the top of cloud)高分辨率场实施变分订正,解决城市热岛研究中高分辨率卫星遥感的客观性订正问题。研究结果揭示了北京城市建筑群面积及中高层建筑群布局对城市热岛群总体演变趋势、多尺度热岛群非均匀分布特征的显著影响效应。结果表明,北京晴空过程城区及近郊区多尺度热岛效应可由强、弱程度不同的热岛群"合成",北京地区热岛分布呈多尺度非均匀特征,即城区东西两侧为强热岛区,城西北园林区与古城中轴线区域为相对弱热岛区;在北京城市高速发展背景下,城郊街区热岛群的非均匀分布特征与城市建筑群布局之间存在着相关关系;城市建筑群面积及中高层建筑密集程度的差异可产生区域性强弱不同的热岛效应,这间接反映出北京城郊中高层建筑群暖气或空调排放热源的局地影响效应。上述研究结果可为城市发展有关建筑群布局与园林绿地规划设计提供科学依据。

To the question which space distribution characteristics and its developed trend of urban heat island in Beijing, a study on general change trend of urban heat island and correlativity between area of urban building clusters, layout of middle or high layer buildings and unsymmetrical spatial distribution of multi-scale urban heat island is discussed. During sunshiny days variation correction is carried out based on air temperature sampled by AWS （Automatic Weather Station） and variational processing method by satellite retrieval high resolution data, TBB （Temperature of Black Body on the top of cloud）. The problem is resolved, which how to correct satellite retrieval data with surface observation data impersonally in the research field about urban heat island. The results revealed that area of urban building clusters and layout of middle or high layer buildings can have remarkable effects on general change trend and unsymmetrical spatial distribution of urban heat island. Analysis results showed that urbanmulti-scale heat island is composed of polycentric and lots of different intensity urban sub-scale heat island clusters as a whole. Multi -scale and unsymmetrical characteristics of heat island is obvious in Beijing. Namely, heat island which is located in east and west of urban districts is strong, but weak in the northeast of urban area which is gardens, greenbelt and middle-axis area of old city. On a background of fast city development, there is the correlativity between unsymmetrical space distribution characteristics of heat island in the urban districts and layout of middle or high layer buildings. Different intensity of heat island reflect indirectly local effect of anthropologic heat which is let out from middle or high layer buildings. Results in this paper can provide scientific basis about distribution of ur- ban building clusters and layout of gardens and greenbelt in the programming of city development.