Research On The Change Law Of Heat Island And Influencing Factors In Yangtze River Delta Urban Agglomeration Based On Satellite Remote Sensing

Urbanization is a necessary stage for the development of human civilization.China's urban development has achieved remarkable achievements on the world stage,and still has great potential.Urbanization can lead the development of civilization,but it also has some adverse effects.Heat island effect is one of the most concerned problems.With the progress and development of satellite remote sensing technology and corresponding image information acquisition technology,it has a new technical foundation to realize this exploration.Most of the existing studies focus on the single time scale changes of cities and urban agglomerations,but there are few studies on the multi time scale changes and influencing factors.Therefore,based on the satellite remote sensing method,this paper studies the change rules and influencing factors of multi time scale heat island effect in the Yangtze River Delta urban agglomeration.It mainly includes two parts: the law of change and the influencing factors.The research on the law of change is carried out from three time scales,namely "day and night-month by month-year by year".The purpose is to integrate these time scales into a "progressive" research and analysis in the same research,so that the time logic of the research has a certain integrity.Firstly,the characteristics of daytime and nighttime heat island effect of each month in 2020 are analyzed qualitatively and quantitatively.It is found that the boundaries of strong heat island and strong heat island in the research area in daytime are more consistent with the suburban boundaries of major cities.The most obvious time is in March,April,July and August,and the most obvious space is in Hefei,Nanjing,Taihu Lake City Cluster,Shanghai and Hangzhou.Correspondingly,by observing the typical river system areas,we can find that all of these areas present negative heat island in the daytime and positive heat island in the night,with Taihu Lake being the most significant.Thus,it is determined that the day is the most obvious period of the day;Then,the spatial and temporal variation characteristics of monthly heat island intensity in 2001,2010 and 2020 are analyzed qualitatively and quantitatively.It is found that in 2001,2010 and 2020,the distribution changes of heat island in the research area in each year mainly have four characteristics: "group north-south migration","individual gathering and scattering distribution","suburban difference evolution" and "stable water land contrast",And it is the most significant in the distribution of heat island in August of each year,so August is the most obvious month of the year;Finally,qualitative and quantitative analysis of the spatial and temporal characteristics of heat island effect from 2001 to 2020 shows that in the past 20 years,strong heat island and strong heat island are concentrated in the urban center and surrounding areas;Most of the water areas are characterized by negative heat island,and the negative heat island area is decreasing year by year;The pixel number of strong heat island and strong heat island fluctuates year by year.The research of influencing factors includes meteorological conditions and social development.In terms of meteorological conditions,based on the meteorological data of meteorological stations,the variation of air temperature,precipitation and solar radiation and their influence on the heat island effect were studied.The results show that: in the past 20 years,all meteorological factors in the Yangtze River Delta region present the law of "fluctuation change".Except the temperature and precipitation in the central region have a certain correlation with the total number of pixels of strong and strong heat island,the others have no significant linear relationship.In terms of social development,based on the relevant data of urban and rural population,social electricity consumption and total economic production of various industries in the social development statistical yearbook,this paper explores the influence of social development factors on heat island effect from two perspectives of spatial distribution and time change.The results show that: in terms of spatial distribution,the comprehensive degree of urban social development presents a gradient law from low to high from west to East.Except for the GDP of the primary industry,the proportion of strong and strong heat island of 18 prefecture level cities(17 prefecture level cities in terms of population)in Central Yangtze River Delta in 2019 has a very significant positive correlation with other social development factors;In terms of time change,in the past 20 years,the social development indicators of the Yangtze River Delta region have changed significantly monotonously,and the correlation between the total number of strong and strong heat island pixels and the data of these social development factors is very significant,except for the negative correlation with the number of rural population,it is positively correlated with other factors.This research can provide meaningful reference for urban agglomeration heat island cognition and governance,as well as regional development planning.There are more than 46000 word,44 diagrams and 12 illustrations.