Length of the active beach profile

[artrob]

Dear benchmark organisers,

Would it be possible to obtain the typical cross-shore length of the active beach profile (distance between MSL contour and the point at which depth of closure is found) ?
This would allow the computation of the overall slope along the active profile, which is required for some longshore sediment transport formulas.
I am asking this because I have the feeling that the beach slopes provided along with this benchmark are steeper than the slope of the active beach profile, as computed within the intertidal zone.
If this is not the case, I would be grateful for a confirmation.

Thanks in advance

Arthur ROBINET (BRGM / French Geological Survey)

[yongjingmao]

Hi Arthur,

Based on Hallermeier (1981) formula, the depth of closure for this site is about 11 m below MSL. The corresponding cross-shore length of the active beach profile is about 500 m, resulting in a slope of 0.022, which is indeed much smaller than the intertidal slope provided.