Fig. 3
Distribution of time-averaged bed shear stress τ meanw (generated by surface wave action) in the Hörnum tidal basin. The highest τ meanw -values, e.g., along the mainland coast, were generated on salt marshes. The reason for those high τ meanw -values is that only times of inundation were taken into account for time averaging. On the salt marshes, flooding only happened when there were strong westerly winds with correspondingly strong wave action. High τw were also generated along the margins of the tidal channels where deeper-water waves “abruptly” came into contact with the shallow bottom of the tidal flat. The τ-scales in this figure and in Fig. 2 are not identical