College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China; Laboratory Cultivation Base of Environment Process and Digital Simulation, Capital Normal University, Beijing 100048, China.
Sci Total Environ. 2021 Jan 1;750:141612. doi: 10.1016/j.scitotenv.2020.141612. Epub 2020 Aug 11.
Transport of suspended particulate matter (SPM) in estuarine waters plays an important role in regulating erosion-accretion and biogeochemical processes. In the Yellow River Estuary (YRE), artificial water and sediment regulation scheme (WSRS) and coastal engineering structures are the 2 typical anthropogenic activities affecting the spatiotemporal dynamics of estuarine SPM. The monitoring of SPM transport affected by such human activities requires SPM mapping at both high spatial and high temporal resolutions. In this study, we presented an improved Flexible Spatiotemporal Data Fusion (FSDAF) strategy with consideration of highly dynamic SPM variations in estuarine waters, and generated 30-m hourly SPM concentrations based on Landsat 8 OLI and GOCI datasets. The new strategy produced higher SPM estimation accuracy than the original FSDAF, with the relative percentage difference (RPD) decreasing from 29.75% to 5.31% using GOCI-derived hourly SPM as reference. With in situ SPM measurements as reference, the fused SPM concentrations had an RMSE of 12.09 mg/L and an RPD of 27.17%. Investigation of interday SPM variations before, during, and after the WSRS in 2018 revealed that the first WSRS significantly increased the SPM concentration and plume extent; new wetland with an area of 12.56 km was formed due to sediment accretion near the river mouth. The two groins offshore from the coastlines on the north and south sides of YRE exhibited obvious sediment trapping effects in that higher SPM concentrations on one side of each groin were found regardless of the turbidity modes and diurnal SPM variations; the trapping effects were associated with the number of groins and groin length. Intraday variations of SPM were influenced by tidal currents, with plume direction following the ebb and flooding tidal current direction. The inter- and intraday characteristics of the 30-m hourly SPM dynamics facilitate the detailed analysis of the sediment transport associated with human activities.
悬移质物质（SPM）在河口水中的输运对调节侵蚀-淤积和生物地球化学过程起着重要作用。在黄河口（YRE），人工水沙调节方案（WSRS）和海岸工程结构是影响河口悬移质时空动态的 2 种典型人为活动。受此类人类活动影响的悬移质输运监测需要在高空间和高时间分辨率下对悬移质进行测绘。在本研究中，我们提出了一种改进的灵活时空数据融合（FSDAF）策略，考虑了河口水中高度动态的 SPM 变化，并基于 Landsat 8 OLI 和 GOCI 数据集生成了 30 米每小时的 SPM 浓度。新策略产生的 SPM 估计精度高于原始 FSDAF，相对百分比差异（RPD）从使用 GOCI 衍生的每小时 SPM 作为参考时的 29.75%降低到 5.31%。与现场 SPM 测量值作为参考相比，融合后的 SPM 浓度的均方根误差（RMSE）为 12.09mg/L，相对百分比差异（RPD）为 27.17%。2018 年 WSRS 前后和期间的日间 SPM 变化调查显示，第一次 WSRS 显著增加了 SPM 浓度和羽流范围；由于河口附近的泥沙淤积，形成了面积为 12.56km2 的新湿地。YRE 南北两侧海岸线上的两个防波堤具有明显的泥沙截留效应，在每个防波堤的一侧发现了更高的 SPM 浓度，而不管浊度模式和日间 SPM 变化如何；截留效应与防波堤的数量和长度有关。SPM 的日内变化受潮流影响，羽流方向随退潮和涨潮潮流方向变化。30 米每小时 SPM 动态的日内和日间特征有助于详细分析与人类活动相关的泥沙输运。
