山东长岛砾石海滩侵蚀及修复

由于自然环境的变化和人类活动的加剧，海岸侵蚀的状况越发严重，近年来国际上砾石养滩作为一种新的海滩养护方法开始兴起，由于其粒径粗、孔隙度大，波浪下渗率较高，起到抵浪消浪的作用，从而形成稳定度较高的海滩，在海滩养护中有着重要的作用。2014年和2016年对山东长岛的砾石海滩做过2次实地调查，研究发现砾石海滩确存在侵蚀现象，滩面下蚀深度最高达到0.6 m，海滩宽度也有变窄的趋势。因此，建议当地采用砾石养滩的方法进行海滩修复，根据当地状况并结合国外砾石养滩的案例可知，砾石抛填的位置应在高潮线以上，填充厚度至少应达到3~4 m，粒径以2~50 mm较好，将滩肩扩宽至30 m海滩能够稳定一段时间。砾石海滩经修复后不仅能够防护海岸，也能够促进当地旅游业的发展，提升城市的品味。

EROSION AND RESTORATION OF THE GRAVEL BEACH AROUND LONG ISLAND,SHANDONG

Due to the changes in natural environment and intensification of human activities, coastal erosion has become a severer challenge to human society recently. Gravel beach nourishment, as a new performance to beach conservation, has rapidly developed in coast defense of the world. Due to its coarse particle size and high porosity, the gravel beach has the capability to filter water out when they are under wave actions. The higher penetration rate of water may make the beach more stable. In 2014 and 2016, the authors conducted two field surveys on the gravel beach at the Long Island, Shandong Province. It is found that the gravel beach there was under erosion, the maximum erosional depth of the beach face was up to 0.6 m, and the width of the beach was narrow. Therefore, it is recommended that the beach be nourished with gravels for beach conservation. According to the local conditions and the cases of some foreign gravel banks, it is known that the location for gravel dumping should be above the high tide line, and the filling thickness should not be less than 3 to 4 meters. The gravels with a diameter of 2-50 mm are the best choice and then widen the beach shoulder up to 30 meters. The beach will remain stable for a period of time as normally required. Governmental management should be strengthened to prevent vandalism. Once the gravel beach is restored, it can not only protect the coast, but also push forward the development of local tourism.