为深入了解湿地植物对近岸波浪的耗散作用,通过物理模型方法,对规则波和不规则波越过岸坡前刚性植被水域的波能衰减进行了试验研究。结果表明:当波浪通过植物区时,有效波高在植物区内逐渐衰减,规则波和不规则波波高消减率分别为29.8%和31.4%;在植物分布密度、波浪周期等参数相同的情况下,刚性植物高度为40 cm,有效波高为8、6、4 cm时,不规则波衰减率分别为41.3%、37.3%和31.3%,规则波有效波高衰减率分别为35%、30.8%和26.1%,无论是规则波还是不规则波,可见入射波浪的波高越大,消波作用越明显;刚性植被高度为40、20 cm植物区的波高(6 cm)衰减率分别为32.3%和21.0%,植物高度越大,波能消减作用效果越好,同样的参数条件,波高h=30 cm的波高衰减率为14.6%,h=40 cm的波高衰减率为9.9%,水深为30 cm时的消波作用优于水深为40 cm时的消波作用,随着水深的增加消波效果降低。本研究结果对于湿地刚性植物与波浪间的相互作用研究提供了参考依据。
A physical model experiment was carried out to investigate energy attenuation of regular and irregular waves including different wave heights,wave periods,water depths,and vegetation heights and densities over the rigid vegetation waters before a sloping beach to understand the dissipation effect of wetland plants on near shore waves. The results showed that the wave height was found to be gradually decayed significantly in the vegetation ar-ea ,with wave attenuation rate of 29.8% in regular wave and 31.4 % in irregular wave. The attenuation rate was 41.3%,37.3%,and 31.3% for irregular wave and 35%,30.8% and 26.1% for regular wave at wave height of 8, 6,and 4 cm under the same plant density and wave period parameters in 40 cm height rigid plants, respective-ly. The more significant effect of wave attenuation was observed as the wave height of incident wave was increased for both regular wave and irregular wave. The wave height attenuation rate was 32.3% and 21.0 % at rigid vegeta-tion height of 40 cm and 20 cm (irregular wave,T = 1 . 2 s, H,=6 cm,h = 30 cm), respectively,the taller vegeta-tion height leading to the larger wave attenuation as well. Under the same parameters,the wave attenuation rates were 14.6% and 9.9% at water depth of 30 cm and 40 cm (H, =40 cm,T =1.0 s, VH =20 cm), respectively. There was higher wave attenuation at water depth of 30 cm than that at water depth of 40 cm,indicating that wave energy attenuation was declined with the increase in water depth. The findings provide reference with research on relationship between rigid vegetation and wave in a wetland.