Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall (M–K) trend test, this study analyzes the linear characteristics and nonlinear behavior of the medium- to long-term shoreline evolution of Jinghai Bay, eastern Guangdong Province. In particular, shoreline rotation caused by a shore-normal coastal structure is emphasized. The results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach, with an average erosion rate of 3.1 m/a, and significant accretion on the northeast beach, with an average accretion rate of 5.6 m/a. Results of the M–K trend test indicate that significant shoreline changes occurred in early 2006, which can be attributed to shore-normal engineering. Prior to that engineering construction, the shorelines are slightly eroded, where the average erosion rate is 0.7 m/a. However, after shore-normal engineering is performed, the shoreline is characterized by significant erosion (3.2 m/a) on the southwest beach and significant accretion (8.5 m/a) on the northeast beach, thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline rotation. Further analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast, but also by cross-shore sediment transport processes. These findings are crucial for beach erosion risk management, coastal disaster zoning, regional sediment budget assessments, and further observations and predictions of beach morphodynamics.

本研究基于 1986 年至 2019 年 87 张 Landsat 卫星图像提取的高潮海岸线数据，利用线性回归率并进行 Mann-Kendall (M–K) 趋势检验，分析了潮汐海岸线的线性特征和非线性行为。粤东静海湾中长期岸线演变.特别强调由海岸正常海岸结构引起的海岸线旋转。结果表明，近30年总体岸线演化特征为西南海滩侵蚀，平均侵蚀速率为3.1 m/a，东北海滩明显增生，平均增生速率为5.6 m/a。 A。 M-K趋势检验的结果表明，2006年初发生了显着的海岸线变化，这可以归因于海岸正常工程。工程建设前，海岸线受到轻微侵蚀，平均侵蚀率为0.7 m/a。但岸线工程实施后，西南海滩岸线侵蚀明显（3.2 m/a），东北海滩岸线增生明显（8.5 m/a），表明岸线工程在西南海滩海岸线侵蚀明显（3.2 m/a）。上升的岬角有助于海岸线顺时针旋转。进一步分析表明，岸线顺时针旋转不仅受到西南向东北的近岸泥沙输送过程的推动，而且还受到跨岸泥沙输送过程的推动。这些发现对于海滩侵蚀风险管理、沿海灾害分区、区域沉积物预算评估以及海滩形态动力学的进一步观测和预测至关重要。