| 摘要: |
| 为掌握滦河口障壁岛的演变特征、为海岛保护与适度利用提供数据支撑，以唐山市龙岛为例，基于RS及GIS技术，分析了近44年来障壁岛的演变特征，并探讨了影响海岛演变的主要因素。分析显示，近44年来海岛面积和长度分别呈减少和增加的趋势，海岛质心位置向西南偏西方向迁移，海岛外海一侧岸线不断后退，平均后退速率达7.37 m/a，其中1978—1984年、1996—2003年、2008—2013年及2018—2019年海岛侵蚀后退明显。研究认为，由于滦河口的自然迁移，河流输沙减少，受沿岸输沙特征影响，海岛主体部分侵蚀而两端沙嘴处堆积，海岛自然状态下已出现5~6 m/a的侵蚀。航道整治挖岛及景区建设挖岛导致近年来海岸典型断面平均后退速率达到研究期内最大值14.27 m/a，海岛长度也出现明显减少，是影响海岛演变的首要因素。滦河流域大型水库的修建使滦河输沙急剧减少，海岛岸线侵蚀加剧、海岛面积明显减少，是研究时段内影响海岛演变的次要原因。风暴潮是影响海岛演变的主要的突发性因素，尤其是2018年内短期内密集过境的台风，造成海岛岸线典型断面平均后退达10.25 m。当前，海岛的保护与适度利用要遵循海岛演变特征，严格禁止不必要的挖岛采砂，并采取海滩修复、构筑透水潜堤等工程措施对重点功能区海岸线加以防护。 |
| 关键词: 障壁岛 龙岛 海岛演变过程 影响因素 |
| DOI：10.11759/hykx20190924001 |
| 分类号:P737.1 |
| 基金项目:河北省科学院科技计划项目（19101）；河北省科学院两院合作项目（191402）河北省科学院人才培养工程资助项目（2019G04） |
|
| Variations and influencing factors of the barrier islands near the Luan River estuary in the past 44 years—A case study of the Loong Island in Tangshan |
|
CHENG Lin, TIAN Hai-lan, LIU Xi-han, WANG Yan-xia
|
|
Institute of Geographic Science, Hebei Academy of Science, Hebei Engineering Research Center for Geographic Information Application, Shijiazhuang 050011, China
|
| Abstract: |
| To provide data support for island management, the variation rules and main influencing factors of the Loong Island in the past 44 years were investigated in this case study. The analysis results showed that the area and length of the Loong Island tended to decrease and increase, respectively. A distinct transfer tendency of the island's centroid was observed, that is, it moved southwest by west. A retreating tendency of the coastline with an average erosion rate of 7.37 m/a was observed on the outer seaside of the island. The maximum erosion rate occurred in 1978-1984, 1996-2003, 2008-2013, and 2018-2019. The erosion rate of the coastline in its natural state can reach 5~6 m/a, which is a result of the sediment shortage caused by the flow of the Luan River. This resulted in the distinct reduction of the length of the island, with the maximum erosion rate of 14.27 m/a of the key profile in 44 years. Channel regulation and scenic spot construction were the first driver of the island's visible variation. Construction of a large water reservoir was the second driver, which led to an accelerated tendency of coastline erosion and island area reduction in 1978-1984 and 1996-2003. In addition, as the main driver, typhoons, particularly those crossing multiple times in a short period (2018-2019), led to a retreat rate of 10.25 m. To ensure effective protection or appropriate utilization, the natural variation rules of these islands should be followed. Moreover, management measures, such as prohibiting sand mining, and engineering measures, including beach nourishment and permeable submerged breakwater, in key functional areas should be taken. |
| Key words: barrier island the Loong Island shape variation influence factors |
