Abstract

The Liaohe River is deficient in runoff and abundant in sediment load, especially due to the joining of the heavily sediment-laden Liuhe River, a perched river channel was formed in the lower reaches, which poses a big threat on flood control. The study shows that the reach above the Liuhe mouth is in a relative equilibrium state of scour and deposition, its discharging capacity varies a little, while the reach below the Liuhe mouth, owing to the Liuhe River’s joining, is in deposition and withered, the discharging capacity decreases over time obviously. The calculation results show that the water amount for sediment transport in the Liaohe River is proportional to the incoming sediment load, and it is 1.615 billion m³ in the upper and middle reaches and 2.622 billion m³ in the lower reaches, which is smaller than non-deposition water amount for sediment transport, showing that the existing water amount in the lower Liaohe River is insufficient for keeping the river channel from consecutive deposition. In order to maintain the relative equilibrium of the lower river channel, some measures should be taken.

Keywords: Liaohe River, scour and deposition, carrying capacity for water and sediment, water amount for sediment transport