Wave friction factor and high-resolution topography of a barrier reef, Mayotte, Indian Ocean

Mayotte (12°50’35” S, 45°8’18”141E) lies to the North of the Mozambique Channel. The present study analyses the data covered on a single cross-barrier transect located in the South West barrier reef of Mayotte Island. A comprehensive field campaign was conducted from August, 25 to October, 1, 2023, and aimed to measure the detailed topography and wave transformation across the barrier reef.

An array of bottom fixed pressure transducers, namely PT1 to PT10, was deployed along a SW-NE cross barrier transect. PT data were used to compute the friction factor for pairs of adjacent sensors. The sensors were configured to continuously monitor bottom pressure at a sampling frequency of 2 Hz. 

A multi-beam echosounder topo-bathymetric survey was carried out to characterize the detailed geometrical structure of the barrier reef over the different reef zonations. 

Mayotte Pairs: PT-pairs wave parameters involved in wave friction computation (wave friction factor fw, near bed orbital excursion Ab, bed horizontal velocity Urms, mean depth D0, rms wave height Hrms, mean period T01, breaker index Gamma, non-linear energy transfers Snl, wave energy flux gradient dECg_dx, Ursell number Ur, dispersion number Mu, burst number Nburst, pair number Ncouple)

 

Mayotte PT: wave bulk parameters for each PT

 

MNT: raw MBES soundings in the barrier zone (ungridded), rotated in the cross-shore/longshore reference of the transect (cross shore X, longshore Y, elevation Z).