1996-2022年黄河三角洲行水河口岸线稳定性研究

Research on the stability of river mouth shoreline in the Yellow River Delta from 1996 to 2022

黄河清八汊现行河口自改汊以来发生了巨大变化,监测其岸线变化,探讨其稳定程度对海岸带可持续发展以及海岸带韧性评估具有重要意义。本研究利用GPS、GIS、RS技术从1996-2022年黄河三角洲行水河口的220幅遥感影像中推断出年平均海岸线位置,同时根据行水河口摆动次数划分为5个阶段,并以此为基础对海岸线变迁及其稳定性进行定量分析。结果表明:行水河口岸线长期处于动态变化过程中,整体呈淤进状态,各岸段岸线时空变化特征不同,最大侵蚀(-73.89m/a)区出现在两丁坝之间,最大淤积(393.20m/a)区出现在河口区附近。研究区90%的岸线表现为较强淤积至严重淤积,稳定性指数由两丁坝之间(0.135)、2007年出汊前旧河口(0.068)、2007年出汊后新生河口(0.006)依次降低。入海水沙量、河口位置变迁以及沿岸输沙是影响岸线稳定性出现时空差异的主要原因。

The current mouth of the Qing8 has undergone tremendous changes since its reconstruction.Monitoring its shoreline changes and exploring its stability are of great significance to the sustainable development of the coastal zone and the assessment of coastal zone resilience.This study uses GPS、GIS、RS technology to infer the annual average coastline position from 220 remote sensing images of the Qing8 from 1996 to 2022.At the same time,it is divided into 5 stages according to the number of swings in the estuary.Based on this,the coastline changes and its stability was quantitatively analyzed.The results show that the shoreline of Qing8 has been in a long-term dynamic change process,and the overall state is in a state of siltation.The spatiotemporal change characteristics of the shoreline of each bank segment are different,and the maximum erosion area(-73.89m/a)occurred between the two groins,the maximum siltation(393.20m/a)area appears near the river mouth area.And 90%of the coastline shows strong to severe siltation.The stability index ranges from between the two groins(0.135),to the old river mouth before the reconstruction in 2007.(0.068),and the New River Estuary(0.006)after the reconstruction in 2007 decreased successively.The amount of sediment entering the sea,changes in the location of the estuary,and sediment transport along the coast are the main reasons for the spatiotemporal differences in shoreline stability.