Peak Water Levels Rise Less Than Mean Sea Level in Tidal Channels Subject to Depth Convergence by Deepening

Effects of sea-level rise (SLR) on future peak water levels in tidal deltas and estuaries are largely unknown, despite these areas being densely populated at high risk flooding. While the rates SLR accelerate, many channels simultaneously experience channel deepening for navigation. With globally decreasing sediment supplies, most becoming deeper when rate accelerates sedimentation cannot keep pace with SLR. These factors potentially favor amplification tides thereby increase flood risk, but extent to which they will do so is unknown. Here, we introduce use a validated model an artificially deepened multi-branch delta get mechanistic understanding non-linear SLR-effects levels. Results show that, current bed level be maintained, not par mean sea-level. Thus increases less than what can expected from predictions increase. The reason that causes proportional reduction convergence area. This mechanism reduces amplification. Nevertheless, effects extend far beyond range present-day seasonal variations, low equal levels, while slightly reduces. have consequences only also freshwater availability, navigation ecology.