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 Huanghuacheng 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,Huanghuacheng 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.