Characteristics of Urban Heat Island Effect of Chengdu

Urban heat island effect is one of the most obvious characteristic of urban climate. Based on geographical information system( GIS) and multi-time remote sensing data,the characteristic of urban heat island effect of Chengdu was studied from spatio-temproal scale according to land surface temperature,heat island intensity and the level of heat island. The results showed that:( 1) The urban heat island effect in Chengdu was obvious,and the intensity was strong in summer and weak in winter at nighttime,and the land surface temperature appeared in strip shapes;( 2) In daytime,the most part of Chengdu was feeble heat island or belonged to the higher grades. The level of heat island in central city was higher in winter,especially at nighttime,and the area of strong heat island expanded compared to that in daytime;( 3) the level of heat island increased and the area of strong heat island expanded from 2002 to 2012,however,the change in heat island intensity and the level of heat island was different among seasons,and the change also was different in day and night time.