Distribution characteristics research of summer urban heat island in Tianjin based on Landsat-8 data

In order to know well the distribution characters of urban heat island areas to seek possible ways to alleviate ur-ban heat island effect,the spatial distribution of summer urban heat island was inverted using mono-window algorithm choosing Landsat8 thermal band data of July 24,2013 and August 25,2013,and then the land surface temperature(LST)was retrieved and the relationship between urban heat island(UHI)with vegetation and water was studied using the method proposed by Senanayake based on the spatial distribution of summer urban heat island. The results show that the average land surface temperature is about 31.5 ℃ in summer,medium temperature area and relatively low temperature area account for the main part of the study area. The LST of heat island area is about 36 ℃ above,the area of heat island area account for 6.12% of the study area,and two centers of heat island area are distributed in downtown and east-central Tanggu be-cause of the nonuniform of spatial distribution,and the landscape pattern is developed to the coexist between group and sporadic distribution,plaque area of heat island have quite different. The vegetation and water area is not covered in the heat island area,and the relieving effect of vegetation and water is remarkable in heat island area which is proved by the relationship among heat island area,vegetation and water using spatial overlay method combined with the examples.