静态平衡岬湾海岸理论中抛物线方程在海滩养护中的应用

岬湾海岸是全球重要的海岸地形,约占全球岸线的51%。岬间海滩又是岬湾海岸地形中最重要的组成部分。20世纪40年代以来,海洋地质学家和海岸工程师们对岬湾海岸做了大量的研究。尤其在20世纪80年代,有关抛物线形状海湾方程的成果发表和后来相关计算机软件的开发,都对判断岬湾岸线稳定性和预测岬头下游海岸的静态平衡起到至关重要的作用。详细介绍了静态平衡岬湾的概念,并且通过在由动态平衡向静态平衡转化、以岸外坝群保护平直沙岸、提高单岬或丁坝下游的稳定性等方面的具体应用,验证了方程的有效性。通过适当的人工构筑物,配合人工养滩,创造静态平衡的海滩,对海岸带的开发和保护具有重要意义。

PARABOLIC EQUATION OF STATIC EQUILIBRIUM THEORY FOR HEADLAND-BAY COAST AND ITS APPLICATION TO BEACH NOURISHMENT

Headland-bay coast is a major type of coastal terrain, which accounts for 51 percent of the coastal line of the world and the headland beach is the most important part of the headland-bay coast terrain. Since 1940s, marine geologists and coastal engineers have devoted a lot of researches to the headland bay coast. Especially, the publication of the parabolic bay shape equation (PBSE) in late 1980s and the development of software MEPBAY in 2003, which have played a crucial role in emulating the shape of a balanced coast and assessing the headland-bay shoreline stability. In this paper, we reviewed the concept of a static equilibrium headland-bay, and its application to the understanding of the transformation between the static equilibrium and the dynamic equilibrium, the protection of the straight sand beaches by offshore breakwaters, and the stability enhancement of downstream of single headland point and spur dikes. The parabolic equation is proven effective for the static equilibrium headland-bay coast. Appropriate artificial structures and static equilibrium beaches are significant to the development and protection of the coastal zone. Limitations and uncertainties of the parabolic bay shape equation are also discussed.