Abstract Rapid intensification (RI) of hurricanes and relative sea‐level rise (RSLR, the combined effect of global sea‐level rise and regional land subsidence) exacerbate compound flood risks by increasing the likelihood of coinciding surge and rainfall extremes. However, their combined influence on flooding remains insufficiently understood. This study examines how RI and RSLR jointly affect compound flooding using hurricanes Harvey (2017) and Beryl (2024) along the Texas Gulf Coast. A reduced‐complexity model efficiently simulates flood dynamics from rainfall, river discharge, and coastal storm surge across diverse coastal settings. Flood attribution metrics reveal distinct mechanisms: Harvey's prolonged rainfall‐driven intensification produced widespread inland flooding with strong rainfall‐flood correlation (r > 0. 7) and amplification, quantified using the compound index difference (CIdiff > 0. 5 m over 75% of Zone 2). In contrast, Beryl's wind‐driven intensification caused surge‐dominated flooding with limited inland compounding. Spatiotemporal analysis confirms that the structure and timing of RI phases critically shape the extent and dominance of flood drivers. A synthetic re‐simulation of Harvey under 2024 sea‐level conditions demonstrates that modest RSLR (∼3–6 cm, 2017–2024) increased flood depths (2–5 cm) and expanded flood extent (∼1. 5%), particularly in low‐lying estuarine areas. While the overall response appears quasi‐linear, localized nonlinear amplification emerges due to topographic thresholds and interacting drivers. These effects were intensified by antecedent hydrologic conditions such as saturated soil and elevated river stages. Our findings emphasize the importance of integrated flood modeling frameworks that account for near‐term sea‐level trends and storm evolution characteristics to inform climate‐resilient flood mitigation and adaptation strategies.
Lee et al. (Wed,) studied this question.