Effect of Artificial Sea Grass on Wave Attenuation- An Experimental Investigation

An experimental study to validate the exponential attenuation of wave height is presented. Coastal vegetation can often attenuate the wave height as well as the wave energy and are, therefore, of interest. The tests were carried out with submerged artificial sea grass vegetation meadow of 2 m length in a wave flume 50 m long, 0.74 m wide and 1.1 m deep. The model plants were prepared from 0.0001 m thick polyethylene plastic sheets with 0.01 m high stipes and 0.21 m long leaves. Regular waves were generated and the wave heights within the vegetation zone measured. For a water depth of 0.40 m, and wave periods 1.8 sec and 2 sec, five different wave heights ranging from 0.08 m to 0.16 m at an interval of 0.02 m were generated. Measurements of wave heights at different locations along the vegetation meadow indicate that as the wave propagates through the sea grass, there is an exponential decay in wave height.