Heuristic Models of Sand Transport in the Surf Zone
Heuristic Models of Sand Transport in the Surf Zone
复制标题
DOI：
--
复制
发表时间：
1973
期刊：
影响因子：
--
通讯作者：
R. Dean
中科院分区：
文献类型：
--
作者：
R. Dean
描述了在冲浪带内的陆上/海上和海岸输沙模式的物理机制。陆上/海上运动模式是基于波浪破碎期间悬浮的初始沙粒在下沉到底部时是否经历了净滨向或向海方向的位移。两个重要的参数是波陡度和落速与波周期之比。利用三位早期研究人员的数据，并选择一个经验常数，发现这两个参数在184次单独实验中有161次可以预测正确的陆上或海上砂粒运动方向。海岸运动模式（沿岸漂移）被认为是海岸流对破碎波浪悬浮的沙子的平流。悬浮沙的数量被认为是在它落到海底的过程中，消耗了进入冲浪区的波浪能量通量的固定部分的数量。平均岸流是基于朗格-希金斯最简单的表示。所得的滨海漂移表达式与先前经验确定的方程非常相似；但这里得到的关系包括海滩坡度、沙粒直径、海滩粗糙度等。这些模型对滩涂修复工程和其他涉及海浪带内沙输运的海岸工程项目具有实用价值。
Physical mechanisms are described for both the onshore/offshore and longshore modes of sand transport within the surf zone. The onshore/offshore mode of motion is based on consideration of whether the initial sand suspended during the wave breaking undergoes a net shoreward or seaward displacement as it falls to the bottom. The two important parameters are the wave steepness and ratio of fall velocity to wave period. Using data from three earlier investigators, and choosing one empirical constant, it is found that these two parameters can predict the correct onshore or offshore direction of sand motion in 161 of 184 individual experimental runs. The longshore mode of motion (littoral drift) is considered to be the advection, by the longshore current, of the sand suspended by the breaking waves. The quantity of sand suspended is taken to be an amount which, during its fall to the bottom, consumes a fixed portion of the wave energy flux into the surf zone. The average longshore current is based on the simplest representation by Longuet - Higgins. The resulting expression for littoral drift is quite similar to earlier empirically determined equations; however, the relationship here obtained includes beach slope, sand grain diameter, beach roughness, etc. These models should be useful in beach restoration projects and other coastal engineering projects concerned with sand transport within the surf zone.