沙质海床形态变化对波浪变形影响的试验

利用水槽试验模拟浅海沙床进行试验，观察波浪和沙床互相作用及其对各自形态变化的影响。通过数据采集及定义两个参数K1（波高变化率）和Kz（沙坝高宽比）的数据处理方法，研究试验现象发生的原因并归纳出规律。试验中海床模型由中值粒径为0．47mm的原型沙铺设而成，坡度为1：20。研究结果表明：波浪在斜坡上的传播受到斜坡高程变化的影响。波浪传播距岸越近，斜坡高程越高，波高越大，同时波峰变尖，波谷坦化。在波浪作用下，底床形成沙纹和沙坝，沙纹和沙坝床面形态的不规则性将对波浪上爬产生一定的阻力，导致平均波高在破碎前减小，最大平均波高发生位置移动，相对波高变化率K1和沙坝高宽比K2之间成正比关系。

Sandy-seabed morphology evolution effect on the wave deformation

Based on the wave flume experiments,the interaction of waves caused by the impact of their morphological changes will be observed. Data collection is used and two parameters K1 （wave height variation rate） and K2 （sandbar aspect ratio） are defined using data processing methods to study the reason of experimental phenomena. The seabed model is used as a prototype sand whose median diameter is 0.47 mm and the slope is 1 ~ 20. The results show that the wave propagation on slopes affected by the slope elevation changes.The closer to shore the wave propagation is,the higher the slopes elevation,and the higher the wave height, while the wave peak becomes sharp and wave trough becomes plain.The sand waves and the sandbar are formed under wave action,the irregularities of the sand waves and the sandbar will be resistant to the wave climbing. The average wave height is decreased before the wave is broken,the maximum average wave height occurs position. A proportional relationship between the relatively wave height variation rate Kland the sandbar aspect ratio K2 is obtained.