Low water temperature sediment transport effects of the hyperconcentrated river: a case study of Bayangaole station in the upper Yellow River

The Yellow River is the river with the highest sediment concentration in the world. The sediment transport of the desert-wide valley reaches in the upper Yellow River are affected by inflow, sediment and changes in topographic conditions. To research the effects of low-temperature water on sediment transport in the hyperconcentrated river, we introduced the water temperature factor to a sediment transport rate model established for the Bayangaole station. Based on the general optimization algorithm of the First Optimization platform, the sediment transport rate model was verified, and the low-temperature sediment transport effect of the hyperconcentrated river was quantified. The results show that: ① The water temperature had an influence on the sediment transport rate mainly in the low water temperature period, especially when the sediment transport rate increased obviously when the water temperature fell below 7 ℃; ② In all conditions, the sediment transport rate at a water temperature of 1 ℃ was approximately 2.5 times that at a water temperature of 25 ℃; ③ The sediment transport rate of the river at a low water temperature (5 ℃) increased by 40.7% compared to that at a normal temperature (16.6 ℃); therefore, in the Upper Yellow River, according to the sediment transport, the best time for water and sediment regulation is during the ice break-up period with low temperatures and high flow conditions. The research results are expected to provide technical support for efficient sediment transport in the low water temperature period of the Yellow River and other hyperconcentrated rivers in cold regions.