【作者】 樊辉；

【导师】 黄海军；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 环境科学， 2005， 博士

【摘要】 本文整合水文站水文观测资料、海面光谱测量及表层悬浮泥沙样品分析资料、拦门沙河段同步定点水文观测数据、遥感影像、水深图及前人文献资料等,借助遥感影像处理、GIS 技术及分形理论等较为系统地研究黄河入海水沙变异特征、入海泥沙扩散输移、河口拦门沙与水下三角洲的演变、岸线与潮滩的变迁及其人类活动对河口泥沙输移与三角洲近期演变的影响。结果表明,由于流域人类活动的影响日益增强,自 20 世纪 70 年代以来,黄河入海水沙量锐减,下游河道频繁断流。通过对黄河口含沙水体光谱反射特性的研究,建立了表层悬 浮 泥 沙 浓 度 遥 感 反 演 的 半 分 析 和 经 验 模 型 。 经 验 关 系 式R TM 3 / RTM2= 0.1683ln(SPM)+0.2454被应用于估测黄河口表层水体含沙量。拦门沙河段水文观测结果表明,潮流区悬沙和底沙交换活跃,最大浑浊带在落急和落憩时发育充分,其范围不超过 10km。采用单窗算法反演 Landsat TM6 影像得到海表温度,并解译出最大浑浊带的位置和范围。黄河口拦门沙是入海泥沙在河口低流速区内大量落淤沉积的结果;拦门沙的形成导致河口河道持续淤高,利津和西河口水位(3000m3/s)年均升高速率分别为 0.164m/a 和 0.170m/a(1985-1996 年)。受以东南向为主潮流输沙和潮流切变锋的控制,70%以上的黄河入海泥沙在河口沉降构建水下三角洲。由于黄河入海水沙的变化,三角洲淤积速率减缓,淤进型海岸减少,仅为蚀退型海岸长度的一半,人工海岸逐年剧增。人为活动也影响了潮滩潮沟的演替进程,潮沟的分维值下降。更多还原

【Abstract】 This paper addresses the sediment transport in the Huanghe River mouth and the recent deltaic evolution, including the changes in water and sediment discharge, sediment transport in the river mouth, river mouth bar formation, subaqueous deltaic evolution, coastline changes and tidal flats’ evolution, in light of hydrological records, field measurements, station-based monitoring, remote sensing interpretation, bathymetric charts and so on. Due to increasing human activities along the Huanghe River drainage basin, the runoff and sediment loads reduced greatly so that seasonal channel dry-ups in the lower reach frequently occurred since 1970s. A semi-analytic spectral reflectance model was presented on basis of previous studies, and some empirical relationships are established between remote-sensing reflectance in Landsat TM bands and suspended sediment concentration (SSC) through in situ spectroradiometric measurements. The best correlation was obtained for the reflectance ratio of Landsat TM3 and TM2, i.e. RT M3 /RTM2= 0.1683ln(SSC) + 0.2454, which was further used to determine SSC in the river mouth. Synchronous hydrological measurement data show that sediment exchanges between the water column and seabed occur down stream from the limit of tidal current in the Huanghe River mouth. The highest SSC value of turbidity maximum appears at the time of maximum or slack ebb tide. Turbidity maximum moves within a range of 10km. In addition, turbidity maximum can be interpreted from sea surface temperature map retrieved from Landsat TM6 via the mono-window algorithm. River mouth bar formation is a consequence of sediment entrapment in the low current velocity zone of the river mouth. Strong riverbed aggradation in the mouth channel is highly related to the river mouth bar progradation. From 1985 to 1996, the water level (at a river discharge of 3000 m3/s) rose at a rate of 0.164 m/a and 0.170 m/a, recorded at Lijin and Xihekou Hydrological Stations, respectively. Through calculating seabed change in the subaqueous delta using GIS software, the results show that more than 70% of sediment loads from the Huanghe River were sequestrated in the river mouth area. The subaqueous deltaic evolution is dominated by SE directed tidal current and tidal shear front in the river mouth. Because of the dramatic reduction in water and sediment discharge since 1986, the progadation rate of the delta, including subaqueous and subaerial, slows down. Natural coast accretion is observed around the active river mouth. Total length of eroded coast is about twice as that of prograded one. In the recent years, land reclamation was prevailed along the delta coast and thus large portion of coasts are changed into artificial coast. As a consequence, fractal dimension value of tidal creeks reduced and the retrogressive succession of tidal flats occurred.更多还原