Stepwise alterations in tidal hydrodynamics in a highly human-modified estuary: The roles of channel deepening and narrowing

•Stepwise alterations in tidal dynamics in terms of wave properties were identified.•Historical development of tidal dynamics were explored using an analytical model.•Enhancement of tidal dynamics can be attributed to the increased channel convergence.•Effects of channel narrowing on tidal dynamics are stronger than those of deepening.•Proposed analytical model is useful for quantifying the impact of human interventions.