Design of the Gold Coast reef for surfing, public amenity and coastal protection: surfing aspects

摘要: The first offshore reef developed to amalgamate world-class surfing, public amenity and coastal protection is described. at Narrowneck Beach on the Gold Coast, Australia, a long, sandy coast experiencing large cyclone waves high net longshore transport. design was based bathymetric wave breaking studies of surfing breaks numerical model predictions. A broad range different shapes numerically tested using refraction, Boussinesq refraction/diffraction sediment transport models. shape that met criteria, for both shoreline characteristics, found be submerged double-sided headland. designed 400 m long extends from natural 2 isobath toe in 10.4 depth, with crest 0.4 below Lowest Astronomical Tide. allowed 'left' 'right' included. Peel angles are rarely less than 40? (in predominant small waves) seabed gradients up 1:12 produce steep plunging faces, making 'fast' 'hollow'. In swell, large, focussing underwater segment will more double deep water height breakpoint. slower 100 shoreward end beginners casual tourists. Because adjacent beaches experience close-out conditions big swells, paddling channel has been placed tip give surfers access during swell. lagoon provides sheltered and, low tide, swimming beach-goers. Wave interference patterns inshore expected provide challenging 'wedgey' body boarders, while placement ideal jumping sailboarder.