Evolution of urban heat island effect in middle and small cities in Sichuan Basin

This paper used four cities - Meishan, Ziyang, Suining and Guang´an - as its research objects. All four cities are located in the middle of Sichuan Basin, closed by each other and distributed along a stripe. The band6 of the Landsat ETM+ Image in two time periods were used to recover the urban brightness temperature so as to disclose the features of their heat island effect and analyze its evolution. As shown by this research, the heat island effect in the cities in the middle of Sichuan Basin is getting stronger along with the cities´ development. The features of the heat island effect have close relation to changes in the process of urbanization. The expansion of urban space and the distribution of industrial zones have evident impacts on the intensity of the heat island. The scale and water body of the cities are the important factors that affect the cities´ heat island effect. So properly increasing water area is an effective way to alleviate urban heat island.