REN Haizhou, REN Zhihui, JIA Menghao, CHEN Lei, DONG Pengfei, WANG Ting
Yellow River.
2025, 47(12):
65-70.
In 2024, the Yellow River Basin faced a severe and complex situation of drought resistance and flood control. The Yellow River Conservancy Commission (YRCC) implemented scientific scheduling, carried out emergency drought-relief regulation of the key reservoir on the main stream of the Yellow River with Xiaolangdi Reservoir at its core, and conducted three flood-season water-sediment regulation processes. This achieved multiple objectives include drought relief, flood control and deposition reduction. Based on the inflow water-sediment data and reservoir operation process, this study analyzed the sediment discharge of the Xiaolangdi Reservoir and the reservoir area’s siltation-erosion changes in 2024. The results are as follows: The annual sediment inflow and outflow volumes are 309.8 million tons and 205.2 million tons respectively, with a sediment discharge ratio of 66.2%. During the three flood seasons, a total of 199.7 million tons of sediment is discharged through water and sediment regulation, accounting for 97.3% of the total sediment discharge for the year. In 2024, the reservoir area is silted up by 116.5 million m3, of which, the main stream and tributaries account for 78.6% and 21.4% of the siltation respectively, with most siltation occurring between elevations of 220 m and 235 m. After the 2024 flood season, the sandbar at the mouth of the Zhenshui River (located 16.39 km from the dam) reaches a height of 5.63 m, resulting in approximately 40.7 million m3 of reservoir capacity in the Zhenshui River being un-utilizable due to the sandbar blockage. It is recommended that in future reservoir operations, measures should be taken to reduce the height of the sandbar at the mouth of the Zhenshui River or slow down its rate of rise, in order to enhance the comprehensive benefits of the reservoir. The scheduling practice in 2024 shows that in order to ensure the water supply for drought resistance downstream, no water and sediment regulation dispatching was carried out before the flood season. However, during the flood season, through scientific optimization, Xiaolangdi Reservoir can still achieve good sediment discharge results.