Ecological Land Cold Island Effect Evaluation Based on Land Surface Temperature Retrieval

The cold island effect caused by urban ecological land can effectively relieve the urban heat island effect brought about by impervious surface expansion. This paper takes Shijiazhuang as the study area and Landsat5 remote sensing image as the data source. It uses RS technology to invert surface temperature and interpret urban ecological land use. On this basis, this paper make the spatial correlation fitting between them, and study the relationship between urban ecological land and surface temperature for different particle size grades and different shape indices, find out the difference between Internal and external surface temperature in the different ecological land types. The results show that there are significant differences in land surface temperature for different types of land use, the lowest temperature is water and the highest temperature is impervious ground. The same types of ecological land use increased with the increase of particle size, and the cooling and cooling effect gradually increased. For different ecological lands, with the increase of particle size, the cold effect in descending order is urban water, urban lawn, and urban forest. The critical regions of cold effect is 1200 meters in urban water, 800 meters in urban forest, and 500 meters in urban lawn. And with the increase of distance, the effect of cold water in urban water is particularly obvious.