重庆市2006年夏季城市热岛分析

ANALYSIS OF THE URBAN HEAT ISLAND IN 2006 SUMMER IN CHONGQING CITY

利用2006年6～8月重庆市区和郊区的26个自动气象站逐小时的观测数据和重庆市地形高程数据等资料,对重庆市夏季的城市热岛效应进行了分析。结果表明,重庆市存在明显的热岛效应,2006年夏季的平均热岛强度值为1.0℃,最大日平均热岛强度达1.8℃。热岛效应的日变化明显,热岛强度夜间强,白天弱,2006年夏季夜间平均热岛强度为1.4℃,夜间最大达到了2.6℃,热岛效应加重了市区夜间的高温热害。高温干旱的出现主要影响夜间的热岛效应,使夜间的平均热岛强度增加了约0.7℃。通过GIS空间化表明,主城区的温度受地形和城市布局的双重影响,高温中心位于城区沿江一带。热岛效应受天气系统影响强烈,当有天气过程时,热岛效应将明显减弱;而在稳定的晴热天气背景下,热岛效应最明显。

The urban heat island intensity in Chongqing from June to August in 2006 was investigated using the data measured at 26 automatic weather stations and the elevation data of Chongqing. The result shows that there is clear effect of urban heat island in Chongqing. Its daily intensity in summer is 1.0 %, with a maximum of 1.8 ℃. The daily variation intensity is very obvious. It is stronger in nighttime than it is in daytime. The average nighttime intensity in summer 2006 is 1.4 ℃, with a maximum up to 2.6 ℃. Damage from high temperature is increased because of the urban heat island effect. Its nighttime intensity increases by 0.7 ℃ on average, which is mostly influenced by high temperature and drought. Using the GIS spatial analysis of temperature, it shows that the temperature distribution is affected by both the landform and functional distribution of the city and the center of high temperature lies along the river through the city. The urban heat island is influenced intensively by weather systems. When there is a weather process, it will decrease dramatically. Under stable, fine and hot weather, however, it is very distinct.