Study On Heat Island Effect Changes In Urban Agglomerations Based On Dense Time Series Analysis Of Landsat

Urban heat island s(UHI)refers to the phenomenon that the temperature of a city is higher than the surrounding temperature,which makes the city like a hot island.Recently,with the increasing speed of China's urbanization,UHI is increasingly obvious.It has become a concern of the local government and scholars.Because the remote sensing technology can observe the urban heat island effect on a large scale and in a long period,many scholars have carried out a large number of studies on the urban heat island effect using multi-temporal or single-temporal remote sensing images.However,current remote sensing monitoring of urban heat island effect ignores the chain effect and gradual feature of urban heat island effect.This paper selects Landsat dense remote sensing image data and takes surface heat island effect of changzhutan urban agglomeration as the research object to discuss the analysis method of urban heat island effect based on Landsat dense time series and the spatio-temporal evolution rule of heat island effect of changzhutan urban agglomerationWe collected Landsat thermal infrared data from 2000 to 2017 to Calculate land surface temperature with the Google Earth Engine platform.Surface urban heat islands was calculated using land surface temperature.The Mann Kendall test(M-K),Theil Sen Median trend analysis(Sen)is the tool for investigation the temporal changed pattern.Standard Deviational Ellipse,and mean center analysis was applied for analysis of spatial variational characteristic.Last,we conducted experiments to analyze the relationship between result of land cover classification,carbon dioxide emission data,plant location data and the spatio-temporal changed of SUHI.(1)The surface heat island effect in changzhutan area is high in summer and low in winter,and the high value appears in the core areas of the city.These core areas are distributed along the xiangjiang river,and the low value is distributed in the surrounding areas of the city.The surface heat island effect value of zhuzhou city is higher than that of xiangtan and changsha ?(2)The center of gravity of SUHI in three cities shows a trend of getting close to each other.The changes of SUHI have spatial differences.The surface heat island effect in the surrounding area and the core area of the city shows an upward trend and a downward trend.(3)The main reason for causing this variation is the change of landcover type.77.125% of all the pixels with an obvious growing SUHI trend has changed to impervious areas.In addition,carbon dioxide emissions and the distribution of highly polluting factories also affect the surface heat island effect.