Analyzing Compound Flooding Drivers Across the US Gulf Coast States

Analyzing flood events has been the focus of numerous studies across local, regional, and global scales, aiming to understand their magnitude, drivers, and spatiotemporal distributions. Traditionally, flood hazards are defined by analyzing the likelihood of flood drivers exceeding their respective thresholds. This approach relies on events around gauge locations with accessible records. The availability of reanalysis and satellite data sets now allows us to leverage data from multiple flood reporting agencies to examine various flood event types, including compound and non-compound events, and their drivers. We analyzed three decades of flood events in the US Gulf Coast states, where compound flood events are common. We found that rainfall is the predominant driver, contributing to over 45% of reported floods classified as compound events. Fluvial and pluvial floods are more frequent and severe during tropical seasons, and especially during the Fall compared with other calendar seasons.