Quantitative study on thermal environment characteristics of urban green land based on remote sensing a case study in Changchun City

Green land plays an important role in mitigating urban thermal environment effects, and the research is significant for optimizing urban function zoning and sustainable development. We selected a typical garden city, Changchun city in northeast China, and extracted vector data of urban land use border and green land by topographic maps in 1990s and Landsat TM images in 1993 and 2005. Moreover, we discussed the thermal environment characteristics of green land, and the influence of patch area and shape on the land surface temperature. The results showed the average differences of land surface temperature between inside and outside green land changed from -1.19°C in 1993 down to -1.64°C in 2005. The differences were prominent in different parts of the same patch and different green lands, which were gradually increased with patch area. Furthermore, improving the shape complexity of green land may help to reduce the land surface temperature.