利用昆明周边多个自动气象站观测的2004-2012年温度序列,研究了昆明城市热岛效应的日、季节和年际变化特征,并分析了昆明城市热岛水平分布和变化趋势。昆明城市热岛强度具有明显的日变化,夜间较强,白天较弱。城市热岛强度一般在早上08:00(北京时间,下同)达到最大值,在午后14:00减弱或消失。城市热岛强度在冬季最强,春、秋季次之,夏季最弱。昆明城市热岛强度多年平均值为1.27°C,在2004-2009年期间表现为逐年递减的趋势,其年际变化的主要影响因子是云量。2004-2007年昆明城市热岛中心主要分布在主城区。2008年以后,由于中小城镇经济和人口的迅速发展,昆明城市热岛面积不断扩大,并出现热岛中心向呈贡、石林一带偏移的现象。
Based on the air temperature data measured by automatic weather stations in the Kunming area during the period 2004–2012, the diurnal, seasonal, and interannual variation in the urban heat island effect in Kunming, its horizontal distribution, and tendency, were analyzed. The results indicated that the urban heat island intensity(UHI) possessed significant diurnal variation, which was larger at night and became weaker during the daytime. Usually, the UHI reached its maximum at 0800 LST, and became weaker or disappeared at 1400 LST. On the seasonal scale, UHI was largest in winter, followed by spring and autumn, and then summer. The annual average UHI during 2004–2009 was 1.27℃, and showed a tendency to decrease in the latter years of the study period due to the increase in cloud. During 2004–2007, the center of the heat island was located in the center of the city, but it seemed to become larger in area and move toward Chenggong and Shilin owing to the rapid growth of the economy and population of medium-and small-sized towns at the county level around Kunming.