Study On Outdoor Thermal Environment Of Towns In Three Gorges Reservoir Region

With the rapid process of urbanization, the urban size and the population are gradually improving. Tall buildings and impermeable infrastructure replace natural surfaces in order to satisfy the needs of people's lives. Towns in the Three Gorges Reservoir Region, which are limited by its mountainous character and have special nature of the climate, are in the rapid urbanization process. Constructions of massive infrastructure affect the outdoor thermal environment in the region. In some towns within the scope of the Three Gorges Reservoir Region, new city construction and old town modification are advancing side by side. Urban planners considered little or directly neglected the influences of urban construction on outdoor thermal environment. What they pursuit is of large capacity of buildings and high-density, making the urban outdoor thermal environment continued to deteriorate. The heat island effect is one of significant performances.This paper selected Wanzhou, Kaixian, Yunyang in the northeast of Chongqing and Huayan new city in the main city as objects for the outdoor thermal environment analysis. During the observation in Wanzhou, Kaixian and Yunyang, moving observation method was employed to record air temperatures on the observation route. The overall air temperature fields were drawn after correcting all the data to be synchronism, and the urban heat island intensities were calculated as well. Both moving observation method and the satellite remote sensing methods were used in the study of Huayan new city to get the spatial and temporal distribution of outdoor thermal environment in the area.A GIS-based information management system for urban outdoor thermal environment was established using the data obtained by the previous observations. The system was introduced, which can be a reference for the information management of the outdoor thermal environment in the towns in the Three Gorges Reservoir Region. Conclusions got in the paper are as follows:1,The maximum urban heat island intensity was about 1.0℃in the daytime in Wanzhou and in Yunyang it's 1.4~1.9℃which were obtained by moving observations. While the urban heat island intensity in the nighttime of Huayan new city was -1.5℃~2.0℃, which approximates to the value in the northeast towns.2,The retrieved surface temperatures from the remote sensing images show that originally scattered high temperature pixels gradually merge into big ones in Huayan new city, which means that the areas of high temperatures have expanded and the internal structure and composition of heat island centers have greatly changed.3,The water body and lakes in the towns of the Three Gorges Reservoir Region has an unapparent effect on lowering the temperature in the daytime. Water body should be considered to improve the outdoor thermal environment during the urban planning and construction, especially lowering the city temperature in summer.4,GIS software can be used for the information management of urban heat island for the towns of the Three Gorges Reservoir Region, which can provide an obvious view of the current outdoor thermal environment and predict the thermal environment trends. The software can be references for urban planning and its sustainable development.