Flood control safety (FCS) is fundamental to sustainable development in river basins facing rapid urbanization and ecological stress. Taking the Haihe River Basin in China as a case study, this paper evaluates the temporal evolution of the three-subsystem development of social, ecological, and flood control safety from 2008 to 2022, and assesses the coupling coordination degree (CCD) of the social–ecological system (SES). The dynamic relationship between FCS and SES coordination is further examined using a panel vector autoregression (PVAR) model, while grey relational analysis with bootstrap resampling is employed to assess the associations between specific FCS indicators and SES coordination. The results show that all three subsystems improved over the study period, and the basin’s CCD increased from severe imbalance to a more coordinated stage. However, FCS remained the relatively weak subsystem, and its constraining role became more evident under the basin-area-weighted assessment. The overall temporal pattern is broadly consistent across different weighting schemes, although the absolute coordination levels vary. The PVAR results indicate that changes in FCS predict subsequent changes in SES coordination, whereas the reverse relationship is not statistically supported. Grey relational analysis further suggests that several FCS indicators, including levee length, reservoir capacity, and soil and water conservation measures, are similarly strongly associated with SES coordination. These findings suggest that improvements in observed coordination do not necessarily indicate that basin resilience has been fully established. Integrating flood control safety into SES assessment can provide a more policy-relevant basis for flood risk governance in highly urbanized and water-stressed basins.
Xu et al. (Thu,) studied this question.