Spatial Analysis Of GDP In The Yangtze River Delta Region Based On Night Light Data

Under the background of economic globalization,the pace of economic development in China is gradually accelerating.It is of great significance to understand the characteristics and laws of economic development for China to plan high-quality economic development.Traditional GDP statistics lack spatial information,so it is difficult to reflect the internal differences of regional economic development.The light information carried by the nighttime light data can break through the regional restrictions and realize the continuous distribution of GDP in smaller geographical units,which can directly reflect the trend and characteristics of economic development.Based on DMSP/OLS and NPP/VIIRS annual nighttime light data,nighttime light data of 1992-2020 long-term time series were constructed in the Yangtze River Delta region.Combined with GDP statistics,the optimal light index and model were selected by correlation analysis and regression analysis to achieve the spatial realization of annual GDP.Using trend analysis,gravity model and other methods to analyze the temporal and spatial characteristics of economic development;At the same time,NPP/VIIRS quarterly data for the first three quarters of 2018-2021 were used to spatialize quarterly GDP and analyze the impact of COVID-19 on the economic development of the region.The main conclusions are as follows:(1)Based on the regression analysis results of DMSP/OLS data in 2013 and ANNUAL NPP/VIIRS data,the highest power function model of R~2was selected to adjust pixel values of annual NPP/VIIRS data from 2013 to 2020,and the constructed long time series nighttime light data had good continuity.Moreover,the GDP simulation results generated by this method have high accuracy,and the average relative error is basically controlled within 4%.(2)From 1992 to 2020,the economic development of the Yangtze River Delta region has a great difference,and the economic development core of prefecture-level cities is closer to the more developed regions,and the DISTRIBUTION of GDP density in urban centers has an obvious sense of hierarchy.Most cities have gradually changed from single-core development mode to multi-core development mode,so does the region as a whole.(3)From 1992 to 2020,the GDP of the Yangtze River Delta region as a whole increased significantly.The GDP of Shanghai,Suzhou-Wuxi-Changzhou metropolitan areas and major provincial capital city centers maintained rapid growth.The southern Anhui and western Zhejiang regions with no significant GDP growth gradually transited to a slower GDP growth stage.(4)From 2010 to 2020,with the expansion of the planning scope of the Yangtze River Delta region,the economic driving capacity of Shanghai is gradually fan-shaped to the surrounding areas,and the radiation scope is also gradually enlarged.(5)After the outbreak of COVID-19,the economic recovery area of the Yangtze River Delta gradually spread from parts of northwest China to the whole region,and began to return to normal economic growth in the third quarter of 2020.The economic trauma of higher economic level area is greater than that of backward area,and its economic recovery period is longer than that of backward area.