Change Of Thermal Environment In Harbin City Based On TM Images

The surface temperature of Harbin City in1989and2010were retrieved from Landsat TM images using the single-window inversion algorithm in this study. The land surface temperature of the city was classified through reference of robust estimation method. Based on landscape indices, the thermal landscape pattern and its spatio-temporal characteristics were analyzed for the whole city and eight districts. The study aims to provide basic data and theoretical basis for urban planning and the ecological environment protection. The studies have drawn the following conclusion:(1) Harbin urban heat island areas were concentrated in the south bank of the Songhua River and the southwest of Harbin intersection zone, and the heat island in Jiangbei District increased significantly with the time going on. From1989to2010, the urban heat island area increased3321.91km2accounting for2.93%of the total area, and the annual change rate was0.15%. The medium thermal environment temperature was dominant in Harbin city, while the sub-high temperature and high-temperature patches were not only small but also highly fragmented. During1989-2010, shape of thermal landscape in Harbin City tended to become more complex. The degree of fragmentation of the high temperature zone was larger, and the thermal landscape shape was most complicated. However, the thermal landscape shape of the low temperature zone was the most simple over the past22years. The difference of the inversed surface temperature between weather station measured temperatures was1.14K in1989and0.74K in2010, respectively.(2) The urban heat island area had different characteristics in different districts. In the typical old town including Nangang District and Daoli District, the distribution of heat island area were centralized, and the heat island area decreased by19.06%and17.71%between1989and2010. While the heat island area in Daowai, Pingfang and Xiangfang District increased10.04%,10.98%and11.27%respectively. The new city of Acheng, Hulan and Songbei had little heat island area.(3) The diversity and uniformity of thermal landscape in Harbin City were at moderate level. From1989to2010, the most obvious changes were found in the Pingfang District, where structure of thermal landscape was more complex and the type of patches were more evenly distributed. Meanwhile, the thermal landscape in Pingfang District was most fragmented and the shape of thermal patches changed dramatically, indicating the thermal landscape had good openness and easier material and energy circulation with surrounding patches. This was inextricably linked with the development of this district and most significant changes driven by human activities in Pingfang.(4) The spatio-temporal characteristics of thermal landscape in different districts of Harbin City had certain correlation with integrated regional development and zoning adjustment.