关键词: NOAA/AVHRR, 数字高程模型, 城市热岛效应, 复杂地形, 重庆

Abstract:

In order to study the characteristics and change rules of the urban heat island (UHI) over complex terrain and to provide reference for urban ecological environment analysis,this article converts the blackbody temperature field into the potential temperature field of the area studied with reference to the thermodynamic concepts and models and with the altitude 300 m as the reference height,based on the digital elevation model (DEM) and fourteen NOAA/AVHRR (National Oceanic and Atmospheric Administration/Advanced Very High Resolution Radiometer) data in 2006 in Chongqing.The results are the following:(1)Intensity of temperature field changes in mountains and valleys;cooling effect of vegetation on the surface is obvious;the scope of UHI is larger in Chongqing in the daytime,the function of the Yangtze River and Jialing River valley’s cutting and separating actions on the UHI is remarkable,and the UHI on both banks of Jialing River becomes a whole body and the scope reduces at night; (2)There are several centers of UHI between July 25 to July 26.Their maximum intensities in the afternoon and early in the morning are respectively 64℃ and 22℃ and the average intensity respectively 605℃ and 205℃.And in such centers,the average intensity between the daytime and the night is 405℃; (3)Average maximum intensities between summer and autumn are respectively 523℃ and 329℃ during day and night; (4)The urban heat island intensity in the daytime is bigger than that at night in Chongqing,which is similar with the study results in Chengdu.But the average maximum intensity between summer and autumn is 426℃,which is lower than that of 650℃ in Chengdu.

Key words: NOAA/AVHRR, digital elevation model, urban heatisland effects, complex terrain, Chongqing