| 摘要: |
| 文章以中街山列岛海洋保护区重点关注的砂质岸段为例，针对青浜岛的沙浦沙滩、二村小沙滩，以及庙子湖岛的东极后沙滩，建立波浪-潮流-泥沙耦合数学模型，研究重点岸段的侵蚀风险隐患，认识岸线演变情况。研究过程中，利用研究区域所在海域实测潮位和潮流观测资料，对模型进行验证，保证模型参数的准确。资料包括2019年12月3日至12月11日期间1个测站潮位资料及6个临时潮流测站完整的包括大、小潮周期的流速、流向观测资料。通过模拟计算重点岸段海滩在遭遇10年一遇极端风浪天气下水下地形的演变趋势，分析重点砂质段的海岸侵蚀风险；采用岸线抛物线模型推算沙浦沙滩、二村小沙滩和东极后沙滩的动态平衡岸线形态，预测沙滩长期冲淤变化趋势。结果表明，模拟浪潮条件下三个沙滩均发生冲刷，冲刷量分别为沙浦沙滩30 m3、二村小沙滩39 m3、东极后沙滩86 m3，建议在该类动力过程（如台风浪）发生后进行人工补沙维护。沙浦沙滩岸线与抛物线模型预测结果基本吻合，沙滩处于相对动态平衡的状态，而二村小沙滩和东极后沙滩的抛物线模型预测岸线在当前岸线的向陆一侧，沙滩岸线处于动态调整并发生侵蚀趋势，建议开展针对性常态化监测。 |
| 关键词: 中街山列岛 海洋保护区 砂质海岸 岸线侵蚀 |
| DOI：10.20016/j.cnki.hykfygl.2024.10.012 |
| 投稿时间：2024-02-05修订日期：2024-10-10 |
| 基金项目:国家重点研发计划项目（2023YFC3008100）；浙江省软课题研究计划项目（2022C35085）. |
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| Research on Beach Erosion Risk and Shoreline Stability: A Case Study of the Zhongjieshan Islands Marine Reserve |
| DING Xuelin,SONG Zekun,ZHANG Zefei,ZHANG Feng,ZHU Yong |
| Marine Academy of Zhejiang Province; Key Laboratory of Ocean Space Resource Management Technology, MNR;Second Institute of Oceanography, MNR;Second Institute of Oceanography, MNR; Ocean College, Zhejiang University |
| Abstract: |
| In this paper, taking the key sandy shoreline of Zhongjieshan Islands Marine Reserve as an example, considering Shapu Beach and Ercunxiao beach on Qingbang Island, and Dongjihou Beach on Miaozihu Island, the coupling mathematical model of wave,tidal current and sediment is established to study the erosion risk in key shoreline sections and understand the evolution of the shoreline. During the research, the model is verified by using the measured tide level and tidal current observation data in the sea area where the study area is located to ensure the suitability of the model. The data include tidal level data at one tidal station and complete flow velocity and direction observations of six temporary tidal current stations during the period from December 3 to December 11, 2019, which includes both spring tides and neap tides. The coastal erosion risk of the key sandy section is analyzed by numerical simulations of the evolution trend of the underwater terrain under the extreme wind and wave conditions with the return period of once every ten years. The dynamic equilibrium shoreline morphology of Shapu Beach, Ercunxiao Beach and Dongjihou Beach is calculated by using the parabolic model of the shoreline, and the long-term erosion and deposition trend of the sandy beaches is predicted. The results show that under the simulated wave conditions, all three beaches are eroded, and the size of erosion is 30 m3 at Shapu Beach, 39 m3 at Ercunxiao Beach and 86 m3 at Dongjihou Beach, respectively. It is suggested that sand recruitment should be carried out manually after such dynamic processes (such as typhoon wave) occur. The prediction results of Shapu Beach shoreline and parabolic model are basically consistent, thus the beach is in a relatively dynamic equilibrium state, while the parabolic models of Ercunxiao Beach and Dongjihou Beach predict the shoreline to be at the land-side of the current shoreline, thus the beach shoreline is in a dynamic adjustment and is likely to be eroded, so it is recommended to carry out targeted monitoring regularly. |
| Key words: Zhongjieshan Islands, Marine protected areas, Sandy coast, Shoreline erosion |
