Difference measurement, source decomposition and spatial-temporal evolution of carbon ecological security in resource-based cities of the Yellow River Basin

The Yellow River Basin is regarded as an important "energy basin" in China. The spatial difference, sources of difference and dynamic evolution of carbon ecological security in resource-based cities were analyzed to optimize the overall layout of the basin's carbon ecological security. An evaluation index system for carbon ecological security of resource-based cities in the Yellow River Basin was constructed, and the TOPSIS model and Dagum Gini coefficient were selected to evaluate the level of carbon ecological security from 2012 to 2021 and analyze the sources of difference for carbon ecological security. The characteristics of spatial-temporal evolution were explored by the kernel density estimation method. The results showed that the carbon ecological security level had been increasing in the resource-based cities of the Yellow River Basin year by year, which had the characteristic of "slight increase - rapid increase", and the carbon ecological security level in the resource-based cities of the upstream region was higher than that in the middle and downstream regions. The spatial imbalance of carbon ecological security in the resource-based cities of different regions was very significant; the regional difference was the main source of the overall difference in carbon ecological security, and the impact of super variable density on the overall difference was increasing. According to the estimation results of the kernel density, the difference in carbon security levels was gradually narrowing among the resource-based cities in different regions of the Yellow River Basin, but the difference in the middle reaches was not obvious. Based on the "carbon peaking and carbon neutrality goals", the resource-based cities in different regions of the Yellow River Basin should formulate different regional carbon ecological security goals and measures to achieve a balance of carbon ecological security across the entire region.