State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158210. doi: 10.1016/j.scitotenv.2022.158210. Epub 2022 Aug 24.
Suspended particulate matter (SPM) concentration is an important biogeochemical parameter for water quality assessment and morphodynamic studies. In this study, the four recent SPM retrieval models developed for Bohai Sea were evaluated using in situ datasets, and the best performing model was selected to investigate the spatiotemporal dynamics of SPM in Bohai Sea from 2011 to 2021 based on 1164 satellite imageries. The results indicated that the satellite-derived SPM concentrations had a high accuracy (R = 0.86, relative percentage difference = 33.71 %). The SPM concentrations in the Bohai Sea demonstrated a significant decadal decreasing trend (0.503 mg/L/yr), and the distribution area with low SPM (<30 mg/L) increased by 3.29 % annually. The southern Bohai Sea declined observably, involving the Bohai Bay (2.07 mg/L/yr), Laizhou Bay (1.916 mg/L/yr), and central Bohai Sea (-0.661 mg/L/yr). Monthly SPM was characterized by significant seasonality. The SPM circulation pattern in the Bohai Strait was generally northerly inflow and southerly outflow. Significant wave heights (Hs) dominated the SPM variations and explained 58.9 % of monthly SPM changes in the Bohai Sea. The strong waves reduction was the main reason for the decadal decline of SPM concentrations. Wind waves associated with monsoons controlled seasonal variations of SPM and promoted the output in winter through the southern Bohai Strait. Storms could cause a sharp increase in SPM concentrations, especially in Bohai Bay and Laizhou Bay which were highly sensitive to northerly winds and strong waves. After the storm ended, the effects of short-duration storm might fade away within a few hours, while that of long-duration storm could last for 2-3 days. High sediment transport from Yellow River (>500 × 10 t/M) controlled 74.8 % of monthly SPM variations within 3-km area off the estuary, 45 % of that within 5-km area, and 28.4 % of that within 10-km area.
悬浮颗粒物（SPM）浓度是水质评估和形态动力学研究的一个重要生物地球化学参数。在本研究中，利用现场数据集评估了为渤海开发的四个最近的 SPM 反演模型，并选择表现最好的模型，根据 1164 景卫星图像，调查 2011 年至 2021 年期间渤海 SPM 的时空动态。结果表明，卫星反演的 SPM 浓度具有较高的精度（R = 0.86，相对百分比差异 = 33.71%）。渤海 SPM 浓度呈显著的十年递减趋势（0.503 mg/L/yr），低 SPM（<30 mg/L）分布面积以每年 3.29%的速度增加。渤海南部明显下降，涉及渤海湾（2.07 mg/L/yr）、莱州湾（1.916 mg/L/yr）和渤海中部（-0.661 mg/L/yr）。月 SPM 具有显著的季节性。渤海海峡的 SPM 环流模式通常为北向流入和南向流出。显著波高（Hs）主导 SPM 变化，解释了渤海月 SPM 变化的 58.9%。SPM 浓度的十年下降主要是由于波高的显著降低。与季风有关的风浪控制了 SPM 的季节性变化，并通过渤海海峡南部促进冬季输出。风暴会导致 SPM 浓度的急剧增加，特别是在对北风和强波高度敏感的渤海湾和莱州湾。风暴结束后，短时间风暴的影响可能会在数小时内消失，而长时间风暴的影响可能会持续 2-3 天。黄河高输沙量（>500×10 t/M）控制了河口 3 公里、5 公里和 10 公里范围内的月 SPM 变化的 74.8%、45%和 28.4%。
