Land subsidence of the Yellow River Delta in China driven by river sediment compaction
Land subsidence of the Yellow River Delta in China driven by river sediment compaction
复制标题
河流泥沙压实驱动的中国黄河三角洲地面沉降
DOI：
10.1016/j.scitotenv.2020.142165
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发表时间：
2021-01-01
影响因子：
9.8
通讯作者：
Zhao, Lihong
中科院分区：
文献类型：
--
作者：
Liu, Yilin;Liu, Jinqing;Zhao, Lihong
由于多种自然和人为原因，世界上许多最大的三角洲正在下沉。这在中国现代黄河三角洲（YRD）尤为明显，它是地球上最具活力的海岸系统之一。长江三峡工程经历了复杂的冲淤过程和严重的压实沉降。然而，时空变化和长期结算率法在这个复杂的三角洲系统仍然知之甚少。显然，表面沉降是由沉积物的长期自然压实过程控制的。我们首先将小基线子集（SBAS）干涉合成孔径雷达（干涉合成孔径雷达）方法与岩土模型和地质，地貌，水文地质和岩土数据相结合，以评估由河流沉积物的固结和压实引发的三角洲范围内的长期时空沉降。卫星和实地观测的结合使我们能够深入了解控制地表运动的主要过程。共75个SAR图像获取的ERS和环境卫星从1992年至2010年被用来生成三个独立的干涉测量子集校准与水平，揭示时空沉降变异。密集分布的时空测量数据使我们能够获得陆地运动的时空变化特征。此外，年平均沉降率在0到>30 mm的范围内。结果表明，三角洲的相对内陆稳定性与海岸边缘的下降趋势形成鲜明对比，平均年沉降率为15 mm。此外，变异性显着相关的三角洲的演变和底土结构的变化。时间序列的干涉合成孔径雷达测量和理论估计的沉降来自岩土模型之间也进行了比较分析。干涉合成孔径雷达测量结果与岩土工程建模结果之间的高度一致性表明，长期沉降（十年至世纪尺度）主要是由河流沉积物的压实驱动的。三角洲次瓣新形成越多，沉降越显著。还确定了在长期存款压实过程中，年沉降率从约70 mm下降到0 mm的趋势。这些发现有助于了解长江三角洲的形态演变，并可能提供洞察世界各地的其他三角洲的变化。(C)2020爱思唯尔B.V.保留所有权利。
Many of the world's largest deltas are sinking due to multiple natural and anthropogenic causes. This is particularly evident for the modern Yellow River Delta (YRD) in China, which is one of the most dynamic coastal systems on Earth. The YRD has experienced complicated patterns of accretion and erosion as well as significant compaction settlements. However, spatiotemporal variability and the long-term settlement rates law in this complex delta system remain poorly understood. Evidently, the surface settlement is supposedly controlled by a longterm natural compaction process of sediments. We first combined the Small Baseline Subset (SBAS) Interferometric Synthetic Aperture Radar (InSAR) method with a geotechnical model and geological, geomorphological, hydrogeological, and geotechnical data to assess the delta-wide long-term spatiotemporal settlement triggered by the consolidation and compaction of river sediments. The combination of satellite and field observations allows us to gain insights into the primary processes controlling surface movement. A total of seventy-five SAR images acquired by ERS and Envisat from 1992 to 2010 are used to generate three independent interferometric subsets calibrated with leveling to unveil spatiotemporal settlement variability. The densely distributed spatiotemporal measurements enable us to acquire the characteristics of the spatiotemporal variations of land movements. Moreover, the annual average settlement rates are observed within a range of 0 to >30 mm. Results suggest that the relative inland stability of the delta contrasts with the decreasing coastal margin trend at an average annual rate of 15mm. Moreover, the variability is significantly correlated with the delta evolution and variations in subsoil architecture. A comparative analysis has also been conducted between time series InSAR measurements and the theoretical estimates of settlement derived from the geotechnical model. The strong agreement between the InSAR measurements and the geotechnical modeled results indicates that long-term settlement (in a decade-to-century scale) is primarily driven by the compaction of river sediments. The more the delta sub-lobe was newly formed, the more significant the settlement. Decreasing trends in annual settlement rates from approximately 70 mm to 0 mm in the long-term deposit compaction process are also identified. These findings are useful to understand the YRD morphological evolution and may provide insights into the changes in other deltas worldwide. (C) 2020 Elsevier B.V. All rights reserved.