Temporal And Spatial Variation Characteristics Of Urban Thermal Environment And Driving Mechanism In Shanghai City

Rapid urbanization has caused significant changes in the intensity of human activities and land use types in urban areas,and the urban thermal environment has undergone dramatic changes,which seriously affects people's quality of life and the sustainable development of cities.It is necessary to strengthen the quantitative research on the urban thermal environment and its driving factors.The land use change and urban thermal environment in Shanghai in the past 20 years were analyzed based on the surface temperature and land use data retrieved from remote sensing images,and the relationship between land surface temperature and land use types was quantitatively studied.By introducing POI point data,the spatial scale effects of land use types and human activity intensity on urban thermal environment were studied to clarify the driving mechanism of urban thermal environment.The results show that:(1)From2000 to 2020,the thermal environment in Shanghai experienced a trend of deterioration first and then improvement,and the temporal and spatial changes of thermal environment are basically consistent with the temporal and spatial changes of land use.(2)During the study period,the average surface temperature of each land use type showed : construction land >grassland > forest land > cultivated land > wetland > water body;The contribution of thermal environment is: construction land > arable land > water > grassland,woodland and wetland.(3)The linear fitting results of area proportion of different land use types and surface thermal environment have large spatial scale differences.For example,the water body is the most significant at 500 m,and the cultivated land is the most significant at 1000 m.The warming effect of construction land increased significantly with the increase of spatial scale.(4)The logarithmic fitting result based on the POI point density is better than the linear fitting result,which is mainly related to the characteristics of the POI data.The research results can provide a scientific basis for rational urban planning and layout.