海坛湾龙凤头海滩养护工程方案

Beach Nourishment in Longfengtou Beach of Haitan Bay

摘要:

福建海坛湾龙凤头海滩宽阔，沙粒细小.20世纪末，由于人工海堤等的修建，导致海滩侵蚀严重，干滩宽度迅速缩小.如何保护沙滩，防止进一步退化变得尤为重要.为解决海滩侵蚀问题，2011年开展了海坛湾沙滩养护一期试验工程，滩肩补沙后海滩侵蚀仍很严重，4个月后岸线平均后退11 m，最大后退量31 m.为解决此问题，提出采取滩肩补沙和实体工程结合的海滩养护方案.运用Generalized Model of Simulating Shoreline Change(GENESIS)建立了龙凤头海滩岸线演变模型，并通过海滩养护一期工程实测资料进行模型率定和验证，模拟值和实测值验证良好.采用验证后的模型，分别模拟了不同新工程方案对岸线演变的影响，并比较分析了方案实施后岸线的演变.结果表明，龙凤头海滩北侧和南侧各增加一个近岸防波堤对研究岸段起到保护作用最为明显，但岸线仍会受到一定程度的侵蚀，可以结合工程后期季节性补沙措施进行防护.

Abstract:

The Longfengtou Beach of Haitan Bay in Fujian Province of China had wide beach and fine sand. Since the end of last century, due to the construction of artificial seawalls, the beach has been eroded seriously, and the dry beach width got shorter. How to prevent the beach from erosion becomes very important. The nourishment trail project in Phase One was put into effect to solve beach erosion in 2011. After the nourishment project, the shoreline still retreated seriously, with an average erosion of 11m and the maximum of 31m in 4 months. In order to solve this problem, beach nourishment and some other engineering schemes are put forward. The evolution model of Longfengtou Beach based on Generalized Model of Simulating Shoreline Change(GENESIS) model is established and verified well with the measured shoreline changes of the nourishment project in Phase One. With this verified model, the shoreline changes with different new engineering schemes are predicted, compared and analyzed. The results indicate that both the north and the south nearshore breakwaters protect the beach, but the coastline still suffers a certain degree of erosion and the schemes should be combined with seasonal beach nourishment to keep the shoreline after the project.