泥沙研究

通常以利津站3 000 m³/s水位作为黄河下游的相对侵蚀基准面，利津水位的升降影响黄河下游的河道冲淤。利津水位的升降不仅受到来水来沙的影响，还与尾闾河长有关。从水流功率角度出发，提出了利津3 000 m³/s流量水位的滞后响应计算方法，较好地模拟了1955—2019年利津水位的历时变化过程，揭示了不同因素对利津水位升降的影响机制。研究还显示，2000年后，利津水位与前期5年滑动平均来沙系数呈显著正相关线性关系，决定系数在0.88以上。小浪底水库运用后，虽然黄河口行河流路尾闾河长持续延伸，但是由于来水量增加，同时来沙量显著减少并保持低值，导致利津断面持续冲刷，利津水位下降。

The water level of Lijin at the discharge of 3000m³/s is often taken as the erosion base level at the Lower Yellow River, the variation of the water level has an influence on the erosion and deposition of the LowerYellow River. However, the rise and fall of the water level at Lijin is not only affected by incoming water and sediment, but also is related to the length of the tail channel. From the perspective of stream power, the delayed response calculation method has been proposed, by which the continuous variation process of water level at Lijin from 1955 to 2019 is well simulated and the underlying influence mechanism of different factors on the rise and fall of Lijin water level has been revealed. The study also shows that after 2000, there is a significant positive linear relationship between the water level at Lijin and the previous 5-year moving average incoming sediment coefficient, with determination coefficient over 0.88. After the operation of Xiaolangdi Reservoir, the tail channel length extended continuously, whereas the water volume inflow increases over time, and the sediment load decreases significantly and maintains at a low value, which leading to continuous erosion in the Lijin section, and the decrease in Lijin water level consequently.