三峡水库蓄水前后皇华城河段水流条件变化及泥沙冲淤分析

皇华城河段位于三峡水库常年回水区,下距三峡大坝354 km。河段平面形态呈"S"形,天然时期呈汛淤枯冲、具有年际间平衡特性。受三峡水库蓄水影响,皇华城河段水位大幅抬升,流速变缓,河势发生较大改变,导致泥沙大量落淤,已成为库区淤积最严重的河段之一。根据实测地形、来水来沙资料,通过统计分析和数学模型相结合的方法,分析了研究河段蓄水前后水流条件变化及泥沙冲淤特性,以及水力学条件变化与泥沙淤积的统计关系,初步预测了河段泥沙淤积的发展趋势。

Flow condition changes and sediment analysis of Huanghuacheng river reach before and after impoundment of the Three Gorges Reservoir

Huanghuacheng river reach belongs to the perennial backwater area,about 354 km from the Three Gorges Dam.The whole type of Huang huacheng reach was "S" shape,presented annual balance features that sediment deposition in flood season and scour in dry season in natural period.Affected by the impoundment of Three Gorges reservoir,Huang huacheng reach became one of the most serious siltation of the river since the water level had a larger uplift,flow velocity became slow,the river regime changed greatly,lead to a large number of sediment deposition.Based on the measured terrain,water and sediment data,the flow condition changes and sediment characteristics of Huanghuacheng reach before and after impoundment of the Three Gorges reservoir are analyzed,the statistical relationship between the changes of hydraulic conditions and sediment deposition are discussed,the development trend of river sediment deposition are forecasted preliminary,through the statistics and analogy analysis together with mathematical model.