Abstract:
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In this project an experimental investigation consisting on the measurement of the wave
patterns and their transformation from offshore into surfzone in the Australian coastline is
presented. The interest of this study is to validate a procedure to obtain field data under
storm conditions that can be compared with mathematical models that need to be improved
and validated for prediction of big natural disasters.
The objectives of the work are first to set up the facility that consists in a series of manometer
tubes ending at different lengths on the sea bed and covering the nearshore and the
surfzone up to 500m. The beginning of the manometer tubes and the recording system are
housed in a bunker buried into the sand. Second, it is intended to process the signals by the
use of sensor calibrations, gain functions and local approximations to estimate the surface
elevation. Finally, the sensor data is to be analysed in the time and frequency domains to
extract the wave patterns and main parameters.
The final tests have been carried out under no extreme weather conditions and the mean
water levels and sensor signals have been recorded. After processing all the measurements,
the mean water levels have been successfully compared to tide levels from a broadwater
buoy. Moreover, wave heights and wave periods have been obtained with different analysis
methods that are presented and discussed in the main text. Interesting wave height
differences between the readings at the 500m tube and at the Gold Coast wave rider buoy
have also been observed. These differences have been compared with the predictions of a
numerical simulation done with SWAN software.
In summary, the system capability and easiness to record data have been proved and
profited to obtain measurements. Furthermore, the signal processing has been successfully
applied to obtain relevant information about nearshore mean water levels and wave
parameters. To finish, future perspectives for following investigations are given. |