Spatial assessment of flow and benefit of tropical cyclone hazard mitigation service

Abstract

Ecosystems are employed to effectively protect people and communities in coastal areas from tropical cyclone (TC) hazards. Although a spatially explicit TC hazard mitigation service (TCHMS) is essential for devising adaptation strategy and resilience policy, the process and delivery of this program are unclear. We improved a capacity–exposure–demand conceptual framework using Guangdong Province, China, as a case study area, and spatial analysis was employed to assess the ecosystem service. Under this framework, we assessed “capacity” as the natural potential protection against TC hazards, “exposure” as the need for services, and “demand” as the estimated necessity of protecting coastal populations and economic interests. The analysis results were then used to map the TCHMS flow and benefit gap. The results showed that 21.6% of the whole province had low capacity, 25.3% had high exposure, and 19.3% had high demand. A significantly negative correlation was present between the TCHMS capacity and exposure, and a positive correlation was shown between the exposure and demand. In particular, the TCHMS flow and benefit were sufficient in inland areas but were severely deficient in coastal megacities. In Guangdong Province, the Pearl River Delta, and Chaoshan (CS), 3.3%, 4.0%, and 15.3% of the areas showed high demand–low capacity–high exposure patterns, respectively. Our findings will deepen the scientific understanding of the degree of protection a given ecosystem will provide to communities and infrastructures exposed to TC hazards and will thus provide scientific support for coastal ecosystem planning and management.