Assessing the impacts of landscape patterns on urban thermal environment based on RS and GIS A case study in Changchun City

The urban thermal environment problems have become more and more serious and prominent with the rapid development of urbanization, and the impacts of landscape patterns on urban thermal environment also become one of the hot topics and key problems in urban ecology. A case study in Changchun in Jilin Province of China was carried out, further analysis referred to quantifying spatial patterns of urban landscape and urban heat field. Moreover, the influence of landscape patterns on the urban thermal environment was discussed. The results showed there were clear differences in the land surface temperature of different kinds of urban landscape types, and the mean surface temperature was the lowest in the surface of water body, the highest was in industrial land, followed by commercial land, transportation land and public land. Furthermore, the landscape of green land was one of the important factors in influencing the distribution of urban heat field, but the patch area of green land was not the main factor to decide land surface temperature, and the mean temperature and the shape index, and the minimum temperature and shape index were positively correlated, whereas the minimum temperature and the shape index of green land is negatively correlated. At the same time, NDVI had larger impacts on LST. Finally, increase of water body area and shape complexity would help to reduce the temperature of water body, additionally, water body could mitigate urban heat island effect, and the scope of its role was within 1100 m away from the water body, the effect of mitigation was obvious within 700 m. The results would be of value to simulate spatial distribution of urban heat field and even put forward countermeasures to lessen the intensity of urban thermal environment.