采砂深度对分汊河道影响分析

Research on the effect of the sand mining depth in a braided channel

以长江天兴洲河段为例,应用一般曲线坐标系下的平面二维水沙数学模型进行研究,并采用实测水沙数据进行率定与验证,模拟了不同流量级下采砂深度不同分流比、水位和流速变化规律,并进一步选取2004年作为典型水沙年,对采砂后河段冲淤变化及采砂区内泥沙回淤率进行预测.模型成果可为本河段采砂的可行性和采砂规模控制提供科学依据.

A 2-D horizontal model with generalized curvilinear coordinates was applied to simulate flow and sediment transports in the Tianxingzhou reach of the Yangtze River. The model was first calibrated and verified using field data. The variations in the velocity distribution and water surface level were then simulated for the conditions of different flow discharges and different depths of sand mining. The model was also used to forecast the change of the reach and the sedimentation efficiency in mining areas after sand mining through selected typical flow and sediment conditions. The results provide necessary information for quantifying effects of sand mining at different scales.