黄河宁夏四排口河段河床冲淤变形的计算

Computation of river bed scouring and silting deformation in the Sipaikou reach of the Yellow River in Ningxia

黄河宁夏平罗四排口"Ω"型河道"裁弯取直"工程的实施,引发了该段河道河床边界条件的剧烈改变。为了掌握工程运行后该段人工开挖引河中水流运动、泥沙运移以及河床迁移演变的发育、演化规律,项目组多次赴平罗黄河四排口进行现场考察与实地取样、测量。根据所研究河段初始地形、流场分布情况以及初步预测的河床变形规律布设了一系列淤积测验断面,随后多次对其展开现场实测,得到了该段河道的河床演变规律、悬移质泥沙粒径和含沙量的分布情况与岸边丁坝影响下河道主流的演进变化规律。依据实测结果计算、分析了工程运行初期河床的平均冲淤变化程度(1.6077m)和河段整体冲刷量(356.4908万m^3),根据分析结果提出了进一步加固丁坝群后左岸岸坡的建议。

The implementation of the"cut and bend"project of the Ningxia Pingluo SipaikouΩ-shaped river channel caused a drastic change in the river bed boundary conditions.In order to grasp the development and evolution rules of water movement,sediment movement,and river bed migration and evolution in the artificial excavation of the river after the project operation,the project team went to the Sipaikou of the Yellow River in Pingluo for site inspections and field measurements.A series of sedimentation test sections were set up according to the actual terrain,current flow conditions,and preliminary forecasted river bed deformation rules of the studied river sections.The subsequent field measurements were carried out to obtain the river bed evolution laws and suspended sediments of this channel,the distribution law of particle size and sediment content,and the evolution of the mainstream of the river under the influence of shoals on the bank.Based on the actual measurement,the average degree of erosion(1.6077 m),deposition of the river bed,and the overall scouring amount(356.4908×10^4 m^3)of the river section were calculated and analyzed.The analysis results suggested the strengthening of the left bank slope of the Spur Group.