Influence of the North Branch of the Qingshuigou River on the Lower Reaches of Yellow River Based on Two-dimensional Numerical Model

The estuary regulation of the Yellow River is closely related to the regulation of the lower Yellow River. The flow and sediment entering the sea block the sediment entering the sea under the action of tidal rise and blocking sand, which has a significant impact on the flood control of the lower Yellow River. In the present study, there are many studies on the analysis of measured data and the empirical formula of inductive reasoning regression, and the use of two-dimensional mathematical model of water and sediment is still rare. In this study, based on the established mathematical model of marine water and sediment in the Yellow River estuary, the typical water and sediment conditions are selected to calculate the sediment movement and siltation erosion in the sea. The calculation results show that under the action of tide and blocking sand, the influence distance of the flow and sediment in the sea on the downstream river is about 90 km-110 km below the Luokou. The flow and sediment in the sea are mainly deposited in the range of 6-8 km along the direction of the flow in the sea near the entrance. The highest point of backwater is in the front of the blocking sand ridge. The backwater surface is relatively steep in the direction of the sea, and the backwater surface is relatively slow in the direction of the river.