Climate risk assessment of Guangxi mangroves under sea level rise and tropical cyclones

Mangrove ecosystems are facing severe threats from accelerated sea level rise (SLR) and the increased frequency of intense tropical cyclones (TCs). Based on the IPCC climate risk framework, this study constructed a comprehensive risk assessment index system for Guangxi's mangroves. Using multi-source data, we assessed climate risks under low (RCP2.6), medium (RCP4.5), and very high (RCP8.5) greenhouse gas emission representative concentration pathway (RCP) scenarios (RCPs) for three major mangrove reserves in Guangxi and proposed adaptation strategies. Key findings include: (1) The combined hazards of SLR and TCs remain relatively low before 2050 but increase significantly by 2100, with SLR becoming the dominant factor (particularly under RCP4.5 and RCP8.5); (2) Exposure and vulnerability exhibit spatial heterogeneity: Maowei Sea Reserve > Beilun Estuary Reserve > Shankou Reserve; (3) By 2100, the proportion of high-to-very-high-risk areas accounts for 74.09% (RCP2.6), 67.66% (RCP4.5), and 93.07% (RCP8.5), respectively; (4) A phased adaptation strategy is proposed: implementing zone-specific measures before 2050, followed by constructing biological revetments, replanting programs, and establishing retreat corridors after 2050. Additionally, wetland elevation management and tropical cyclone impact assessments should be enhanced in Maowei Sea and Shankou reserves to improve climate risk governance.