Analysis Of The Characteristics And Driving Mechanism Of The Heat Island Effect In The Urban Area Around Dianchi Lake

Heat island effect,which affects urban ecological environment and urban climate,is one of the important ecological environmental problems faced by urban development at present.In this paper,the important experience of heat island effect research at home and abroad in recent years is summarized,based on the image data,the urban surface heat temperature is calculated,the spatial distribution and time evolution of urban heat island are analyzed by geo-information system,the driving mechanism of heat island effect is analyzed by statistical analysis of data.In this paper,Dianchi waters and Kunming main urban areas are selected as the study area,which includes seven main areas:Guandu district,Xishan district,Panlong district,Wuhua district,Chenggong district,Jinning district and dianchi Lake Water area.In this study,Landsat8 remote sensing images from 2014 to 2018 were selected as the basic data.Using remote sensing technology to calculate surface temperature based on image data,the sample points are taken and the temperature is measured in the corresponding time period.the measured results are used to verify the accuracy of the calculation temperature.Land cover parameters such as building index,vegetation index and water body index were extracted by band calculation method.The time evolution and spatial distribution characteristics of heat island effect around lake in Kunming city were obtained by statistical analysis of land surface temperature,vegetation cover,building cover,water cover and other parameters in five years by using geographic information technology.The data of population,population density,vegetation cover index,building cover index,water body cover index and surface temperature were analyzed,the analysis methods include correlation analysis and principal component analysis.The results of this study show that:?In the last 5 years,the surface temperature of the study area generally showed an upward trend,with the largest change in Guandu and Chenggong areas,and the smallest change in Dianchi Lake areas;The spatial distribution of heat island mainly takes the construction dense area as the center,extends from the city center to Changshui airport and extends from the city center to the Chenggong area,and these two regions have the most obvious heat island effect;The distribution form of heat island in Changshui airport is strip distribution,while the distribution of heat island in Gongong area is lamellar distribution?The heat island effect in urban area is polarized,the area of middle temperature area decreases,the area of low temperature area and high temperature area increases,and the temperature increase of most urban areas changes into high temperature area and subhigh temperature area.The diffusion rate is the fastest in the sub-high temperature region,with an average annual growth rate of 0.53%?The surface temperature is generally increasing from 14 years to 18 years There is a negative correlation between surface temperature and NDVI value,a positive correlation between NDBI index and surface temperature,and a negative correlation between water body index and surface temperature?Population factors and building index have the greatest driving effect on heat island effect,human activities and architecture can promote the formation of heat island,and the force is large.The distribution of vegetation and water body in urban area can alleviate the urban heat island,but the force is much lower than that of human activities and construction area.