Urban Heat Island Effect Research And System Design Based On Remote Sensing Image

Urban heat island effect is one of the important manifestations of urban ecology.Urban heat island effect causes high temperature inside the city,which seriously threatens the physical and mental health of the residents.At the same time,it will cause air pressure difference between urban and rural areas and cause air circulation,making it difficult for pollutants in urban areas.The proliferation will increase the internal pollution of the city;at the same time,it will also increase the energy consumption of the city.In general,the impact on the urban residents and the ecology will do more harm than good.Tropical coastal cities are affected by geographical location and marine climate,and in recent years,due to land development in the Haikou region and reclamation of islands,they have shown their unique multi-factor correlations,which have an important impact on the underlying surface structure and ecological environment.Further study of the heat island effect.The surface temperature inversion algorithm is the key point to study the urban heat island effect.Through comprehensive analysis of common heat island effect inversion algorithms,the radiation transmission equation method,Landsat TM/ETM+ single window algorithm,TIRS10 single window algorithm and universal single channel are selected.The algorithm is used as a research area inversion algorithm,and the accuracy of Landsat 8 image inversion retrieval in Haikou region in 2015 is selected.The surface temperature distribution maps of the four algorithms are obtained and compared with the on-board brightness temperature of the region and the actual temperature of the day.The results show that the TIRS10 is single.The window algorithm is more suitable as the research area inversion algorithm;in order to facilitate the dynamic monitoring of ground temperature inversion,this paper also designs the surface inversion system,and completes all the research work of ENVI,ArcGIS.Landsat 8 OLI/TIRS data of the three phases in 2013,2015 and 2017 are respectively used for surface temperature inversion.From the perspective of spatial distribution,the heat island effect in this area is very low,accounting for only 0.49%of the total,accounting for the largest concentration In the downtown area,however,with the increase of years,the heat island area is in a trend of increasing radiation,and by 2017 there are two more heat island areas caused by man-made land-filling.In this study,different phases of the same month were studied and found that at The heat island effect around June is more obvious than the heat island effect around January;Analysis of the characteristics of the study area shows that reasonable planning helps to alleviate or reduce the expansion of the heat island effect.From the aspects of vegetation cover,water body index,distance from coastline and impervious surface,this paper studies the driving mechanism of the heat island in this area.Through the spatial sampling,the regression equation between surface parameters and surface temperature is established.It is found that except for the distance from the shoreline,There was a linear relationship between the three factors and the ground temperature,of which the vegetation cover and water body index were negatively correlated with the ground temperature.The average NDVI increased by 0.1 and the surface temperature decreased by 1.17 ?.The normalized difference water body index MNDWI)increased by 0.1 and the ground temperature decreased by 0.79 ?.For each 0.1 increase in the normalized impervious surface index(NDISI),the temperature in the study area increased by 4.6 ?.Through the study of the causes,distribution and influencing factors of urban thermal environment in Haikou,some suggestions for relieving urban heat islands are put forward,which will provide auxiliary functions for urban construction and the formulation of related policies.