Abstract:
The geometric characteristics of sand waves in the main channel of the outer Tagus estuary are
investigated, using high-resolution surveys conducted in 2019 and 2020. The relationship
between bedform height and spacing over a 1400 m transect, at ca. 20 m depth, is in good
agreement with the global mean trend equation proposed by Flemming (1988). The consistent
ebb-oriented asymmetry suggests that the direction of net sediment transport is seaward. The
apparent direction of sand wave migration obtained from the comparison between surveys is
more variable, but on average also ebb-oriented.
