We found that tidal damping in an estuary becomes important once the estuary depth (i.e. Cross-section averaged depth at low water) becomes lower than 4.2 – 7.7 m, depending on the estuary-convergence. Similar results were found for the habitat analysis: once the area of the deep subtidal habitat (> 5 m below low water) becomes smaller than 20 %, and the area of the shallow subtidal habitat (< 5 m below low water) becomes larger than 35 %, tidal damping in an estuary prevails. Concerning SPM, turbidity maxima are associated with maxima in tidal energy. We further found that these high SPM values force tidal marshes to faster attain a high climax vegetation state with less plant diversity.