新干枢纽下游河床冲淤及航道条件变化计算

Analysis of riverbed erosion and waterway conditions' change downstream Xin' gan hub

根据赣江流域规划,在赣江下游三湖镇河段规划兴建新干航电枢纽,枢纽建成后坝下游的河床冲淤及水位变化需要进行预测研究。建立了坝址至南昌118 km长河段的一维水沙数学模型,计算了拟建新干枢纽坝下河道河床下切与水位下降情况。结果表明：在现状河道条件下,经过6～7个水文年河床调整后,枢纽下游河段河床冲淤接近平衡;经过10个水文年作用后,新干枢纽坝址下游附近河段河床最大冲刷深度为1.76 m,坝址下游附近水位最大下降值为1.56 m。分析了河床调整后坝址至南昌河段航道条件的变化。

According to the river basin planning of the Ganjiang river, the Xin＇ gan navigation electricity hinge will be proposed at about 1.5 km upstream from Sanhu town. It must be predicted that the change tendency of river bed and water levels downstream hub after completion of the project. The 1-D flow and sediment mathematical model are established from Sanhu town to Nanchang for 118 km long reach. The deformation of river bed and the declining water levels are computed by numerical model after completion of the project. The conclusion shows that under the current river status, the river bed will reach a equilibrium state by scouring and deposition for 6 - 7 hydrological years; the maximum scour depth of the river bed will be 1.76 m and the maximum value of the declining water levels will be 1.56 m after the self-adjustment of river bed about 10 hydrological years. The change of waterway condition downstream of the Xin＇ gan hub is analyzed.