Coupling and decoupling of humans and the built environment under disaster disturbances.

This study, based on the context of rainstorm and flood disasters, explored the coupling, coordination, and decoupling between humans and the built environment. Combining the coupling coordination model with the Tapio decoupling model, the coupling situation in 16 prefecture-level cities in Anhui province from 2009 to 2020 was analyzed. A random forest method combined with recursive feature elimination was used to identify key driving factors. Constraint line extraction and elasticity analysis were used to determine the response and threshold of the coupling coordination to these driving factors. The results showed an overall upward trend in the coupling coordination of the 16 prefecture-level cities, and in most years, the decoupling between humans and the built environment exhibited varying degrees of coupling intensity. Using the decoupling index (DI) of 0.8 and 1.2 as classification thresholds, the vast majority of the sample exhibited a developmental decoupling pattern, with only a few cities exhibiting a decline-type decoupling pattern in a few years, which is generally consistent with the changing trend of the coupling coordination. GDP, urbanization rate, number of people with college or higher education per 100,000 people, economic losses from flooding, population affected by floods, length of drainage pipes, registered urban unemployment rate, and number of medical institutions are important drivers of changes in the coupling coordination degree. This study provides important insights into the relationship between people and the built environment in the context of heavy rain and flooding, and offers valuable reference and guidance for research and practice in related fields.