Supply–demand assessment of ecosystem-based disaster risk reduction capacity: Focusing on drought and flood risks

Study region Henan Province, China. Study focus The potential of ecosystem-based disaster risk reduction to simultaneously mitigate drought and flood risks remains insufficiently understood. This study developed a framework to jointly assess the supply–demand matching of ecosystem-based drought disaster risk reduction capacity (Eco-DDRR) and ecosystem-based flood disaster risk reduction capacity (Eco-FDRR). Supply was represented by risk-reduction ecosystem services and demand by the hazard–exposure–vulnerability framework. The Eco-DDRR and Eco-FDRR supply–demand matching indices, denoted as D-SDI and F-SDI, respectively, were further used to examine their associations, dependence structures, and co-occurring state probabilities. The results were then used to assess potential synergies, trade-offs, and differentiated management needs across cities. New hydrological insights for the region Several cities showed positive associations between D-SDI and F-SDI, with some exhibiting upper-tail dependence. This indicates a stronger tendency for high matching levels to co-occur and suggests potential for coordinated improvement of D-SDI and F-SDI. D-SDI declined across most of the study area, whereas F-SDI generally increased, suggesting a priority for improving Eco-DDRR supply–demand matching. In addition, slight mismatch in both D-SDI and F-SDI was the dominant co-occurring state in most cities, while other high-probability state combinations varied considerably across cities, supporting classification into five management types. Overall, the framework highlights the potential of ecosystem-based disaster risk reduction for integrated drought–flood risk management and offers a hydro-ecological perspective for developing disaster-resilient cities.