| 摘要: |
| 受自然变化和人类活动影响,全球海滩普遍侵蚀。研究基于大量卫星图像评估海滩演变的方法,对于缺乏实测资料的海滩的侵蚀防护具有重要意义。使用1984~2021年的993幅卫星图像,采用聚焦剖面的亚像素海岸线识别方法识别水边线和干湿线位置,进一步得出平均高、低潮线,沟槽中线和沙坝坝顶位置,利用多指标重建汇泉湾海滩地形地貌的时空演变。使用固定地物对Sentinel卫星图像进行了地理精校正,基于海滩实测结果评估了海滩岸线位置误差。结果显示,平均高潮线、沟槽中线和沙坝坝顶的系统误差和随机误差以及平均低潮线的随机误差均较小,但平均低潮线的系统误差偏大。研究结果还揭示青岛汇泉湾海滩近40年的地形和地貌演变主要受人类活动影响。海滩平均高潮线在2003年海滩整治和补沙后由稳定转为蚀退,在2017年海滩补沙后淤进减缓;沙坝和沟槽的演变则与2002年海滩东南部码头拆除有关。建议重视研究区沙坝和沟槽近期变化,定期监测以进一步掌握其演变规律,并向沙坝和沟槽补细砂维护汇泉湾海滩。 |
| 关键词: 海滩演变 卫星图像 海滩剖面 水边线 干湿线 沙坝和沟槽 |
| DOI：10.11693/hyhz20211100286 |
| 分类号:P737.1 |
| 基金项目:山东省自然科学基金,ZR2019MD037号;国家自然科学基金,41776059号。 |
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| TOPOGRAPHIC AND GEOMORPHOLOGICAL EVOLUTION OF HUIQUAN BEACH OF QINGDAO IN PAST 40 YEARS USING MASSIVE SATELLITE IMAGES |
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ZHANG Xiao-Dong1,2, YAO Yu-Han1, ZHU Long-Hai1,2, HU Ri-Jun1,2, WU Chuang1
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1.College of Marine Geoscience, Ocean University of China, Qingdao 266100, China;2.The Key Lab of Submarine Geoscience and Prospecting Techniques, Ministry of Education, Ocean University of China, Qingdao 266100, China
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| Abstract: |
| Under the influence of natural change and human activities, beach erosion is common all over the world. Studying the evolution of beaches using satellite images is important for the beach protection. In this case study on the Huiquan Beach, Qingdao, 993 local satellite images taken in 1984 to 2021 were used to determine the positions of waterline and dry/wet line along several transects using subpixel shoreline recognition technology. The mean high- and low-water lines, trough center, and bar crest positions were obtained, from which the spatial and temporal topographic and geomorphological evolution of Huiquan Beach was elucidated using above-mentioned multiple indicators. The Sentinel satellite images were further geographically corrected using fixed ground features, and the error of beach shoreline position was evaluated by using field measurement data. The systematic and random errors of the mean high-water line, trough center, and sand bar crest, and the random error of the mean low-water line are relatively small, while the systematic error of the mean low-water line is relatively large. In addition, the topographic and geomorphological evolution of the beach in past 40 years is mainly affected by human activities. The mean high-water line changed from stable to erosional after the beach remediation in 2003, and the silting of the mean high-water line slowed down after the beach remediation in 2017. Meanwhile, the evolution of the bar and trough is related to the demolishment of an old dock (built in 1957) southeast to the beach in 2002. We suggest to focus on the recent changes of the bar and trough by regular monitoring to understand the variation rules, and replenish fine sands onto the bar and trough for better remediation of the Huiquan Beach. |
| Key words: beach evolution satellite image beach profile waterline dry/wet line bar and trough |
