The Yellow River (YR) is famous for its high sediment concentration. The Xiaolangdi dam (XLD),the most downstream dam on the mainstream of the YR, plays an integral role in siltation mitigation, flood defence, agriculture, and hydropower generation. To alleviate siltation of the Xiaolangdi Reservoir (XLDR) and riverbed uplift of the lower reaches of the YR and strengthen flood control safety downstream, the XLDR began to implement water-sediment regulation in 2002. Water-sediment regulation (WSR) has significantly changed the hydrological processes, erosion and deposition, and sediment transport in the downstream channel, and the downstream water environmental conditions have also changed. In this study, 10 sections in the Lower Yellow River (LYR, from the XLDR to the Lijin section) and 4 sections in the soft floodplain area were sampled in the field to analyse their surface sediment grain size composition and nutrient content. At the same time, data on the average annual median particle sizes (D₅₀) of channel sediments and suspended particles in 7 typical sections in the LYR from 2004 to 2015 were statistically analysed. The results show that the channel sediment grain size in the LYR decreased along the river course, and the D₅₀ ranged from 0.20 mm in the HYK section to 0.08 mm in the LJ section. Moreover the D₅₀ of the suspended sediment was less than 0.05 mm. The D₅₀ of the channel and suspended sediment were both ranked as follows: non-flood season > flood season > WSR period. After WSR, fine silt particles with diameters of 0.01-0.05 mm were deposited on the soft floodplain. The channel sediment size was mainly coarse particles with diameters of 0.05-0.20 mm due to channel erosion. The suspension of fine silt particles due to flood scouring led to the total organic carbon (TOC) and total nitrogen (TN) absorbed in the particles to also be resuspended in the water. As a result, the TOC and TN contents in the channel sediments decreased by approximately 40% after WSR.

黄河（YR）以高的泥沙浓度而闻名。小浪底水坝（XLD）是黄河干流中最下游的水坝，在减缓泥沙淤积，防洪，农业和水力发电方面发挥着不可或缺的作用。为了减轻小浪底水库的淤积和黄河下游河床的隆起并增强下游的防洪安全，XLDR从2002年开始实施水沙法规。水沙法规（WSR）大大改变了水文过程，侵蚀和沉积以及下游河道中的泥沙输送以及下游水环境条件也发生了变化。在这项研究中，黄河下游（LYR，从XLDR到利津段）和软洪泛区的4个段在田间取样，以分析其表层沉积物粒度组成和养分含量。同时，获得年平均中值粒径（D统计分析了2004年至2015年LYR 7个典型断面中₅₀％的河道沉积物和悬浮颗粒。结果表明，LYR河道的沉积物粒径沿河道减小，D _50的范围从HYK段的0.20 mm到LJ段的0.08 mm。此外，悬浮沉积物的D ₅₀小于0.05 mm。D ₅₀航道和悬浮泥沙的排位依次为：非汛期>汛期> WSR期。WSR后，直径为0.01-0.05 mm的细粉尘颗粒沉积在软洪泛区上。由于河道侵蚀，河道沉积物的大小主要是直径为0.05-0.20 mm的粗颗粒。由于洪水冲刷，细粉尘颗粒的悬浮导致颗粒中吸收的总有机碳（TOC）和总氮（TN）也重新悬浮在水中。结果，WSR后通道沉积物中的TOC和TN含量降低了约40％。