Analysis of the differences and spatial-temporal dynamic evolution of the environmental sustainability of the Yangtze River Economic Belt in China

The Yangtze River Economic Belt (YREB) is a pioneering example of ecological civilisation construction in China; thus, the environmental sustainability of the YREB is important for advancing China's national level of environmental sustainability. To achieve this goal, we propose an evaluation index system to measure the environmental sustainability levels of the 11 provinces and cities in the YREB and analyse their upper, middle and lower regional differences and spatiotemporal dynamic evolution characteristics according to an integration of Dagum's Gini coefficient decomposition method, kernel density estimation, Moran's I and the Markov chain. The results show that during the period from 2003 to 2020, the following occurred: first, the average environmental sustainability level of the YREB steadily increased. Second, the difference in the environmental sustainability level of the entire YREB decreased, whereas the intraregional- and interregional differences were the sources of differences in the environmental sustainability of the YREB. Third, there was no significant spatial correlation between the environmental sustainability levels of the regions.