The propagation of fluvial flood waves through a backwater-estuarine environment Water Resources Research

Most coastal cities and ports are located along rivers near the sea and are increasingly vulnerable to flooding from both sources due to intense development and sea level rise. River discharge is measured far inland where deltas, estuaries, and marine forces do not interfere, but these same influences make it difficult to observe when and how much flooding occurs near the coast. Usually in rivers, large flooding events move from upstream to downstream faster than small events. A study was conducted to track flooding events through a coastal environment using long‐term observations in Alabama. In contrast to flooding behavior in rivers, the results showed small flooding events moved downstream faster than large events. This occurred because large events caused water to flow out of the river channel, spilling over the forested floodplains where it traveled more slowly. This flooding of the delta also decreased the impact of large events and demonstrates large river discharge events can be tracked in coastal areas. These findings indicate stakeholders can decrease the intensity of coastal flooding and provide more time to prepare by allowing inland regions of rivers to flood and/or by managing vegetation type, both of which reduce the downstream height of water. Grant no. NA17NOS4510101