Projects per year
Abstract
The secondary wave field associated with undular tidal bores (known as whelps) has been barely studied in field conditions: the wave field can be strongly non-hydrostatic, and the turbidity is generally high. In situ measurements based on pressure or acoustic signals can therefore be limited or inadequate. The intermittent nature of this process in the field and the complications encountered in the downscaling to laboratory conditions also render its study difficult. Here, we present a new methodology based on LiDAR technology to provide high spatial and temporal resolution measurements of the free surface of an undular tidal bore. A wave-by-wave analysis is performed on the whelps, and comparisons between LiDAR, acoustic and pressure-derived measurements are used to quantify the non-hydrostatic nature of this phenomenon. A correction based on linear wave theory applied on individual wave properties improves the results from the pressure transducer (Root mean square error, RMSE of 0.19 m against 0.38 m); however, more robust data is obtained from an upwards-looking acoustic sensor despite high turbidity during the passage of the whelps (RMSE of 0.05 m). Finally, the LiDAR scanner provides the unique possibility to study the wave geometry: the distribution of measured wave height, period, celerity, steepness and wavelength are presented. It is found that the highest wave from the whelps can be steeper than the bore front, explaining why breaking events are sometimes observed in the secondary wave field of undular tidal bores.
Original language | English |
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Article number | 462 |
Pages (from-to) | 1-14 |
Number of pages | 14 |
Journal | Remote Sensing |
Volume | 9 |
Issue number | 5 |
Early online date | 10 May 2017 |
DOIs | |
Publication status | Published - 31 May 2017 |
Keywords
- undular bore
- non-hydrostatic processes
- LiDAR scanner
- wave-by-wave analysis
Fingerprint
Dive into the research topics of 'High Frequency Field Measurements of an Undular Bore Using a 2D LiDAR Scanner'. Together they form a unique fingerprint.Projects
- 1 Finished
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Waves in Shallow Water
Blenkinsopp, C. (PI)
Engineering and Physical Sciences Research Council
15/02/16 → 8/10/17
Project: Research council
Profiles
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Chris Blenkinsopp
- Department of Architecture & Civil Engineering - Senior Lecturer
- Water Innovation and Research Centre (WIRC)
- Centre for Climate Adaptation & Environment Research (CAER)
- Institute of Sustainability and Climate Change
Person: Research & Teaching, Core staff, Affiliate staff
Datasets
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Dataset for "High-resolution monitoring of wave transformation in the surf zone using a LiDAR scanner array"
Blenkinsopp, C. (Creator) & Martins, K. (Creator), University of Bath, 14 Aug 2018
DOI: 10.15125/BATH-00540
Dataset