基于分形插值方法的长江口深水航道回淤量计算

Calculation of backsilting quantity in Yangtze Estuary deepwater channel based on fractal interpolation method

基于分形插值方法在时间尺度上对长江口12.5 m深水航道2011至2013年的回淤量进行研究。分析垂直尺度因子对年回淤量的影响,给出年回淤量的计算公式,预测和评估长江口航道的年回淤量。研究结果表明,分形插值可以较好的反映长江口12.5 m深水航道的月回淤量的变化,通过调整垂直尺度因子,可以得到包含动力和泥沙特性在内的综合因素对深水航道年回淤量的影响。基于分形插值方法构建了长江口深水航道年回淤量计算公式,可以依据垂直尺度因子di对长江口航道年回淤量进行相对准确的预测和评估。确定了垂直尺度因子的变化范围为-0.12至0.20,进而得到近些年的年回淤量的变化范围为8 023.7×104m3至10 303.2×104m3,其最小回淤量为6 580×104m3。

The backsihing quantity in the Yangtze Estuary deepwater channel is interpolated based on fractal interpolation method with calculating annual siltation from 2011 to 2013. The vertical scale factor can be used to analyze variety of annual siltation. The annual backsihing quantity is forecasted and estimated by fitting a formula. The results show that the fractal interpolation can reflect the variation of monthly siltation in the Yangtze Estuary deepwater channel. The influence of comprehensive factors including dynamics and sediment characteristics on annual siltation in deepwater channel can be got by adjusting the vertical scaling factor. Last, a formula on the basis of the vertical scale factor （ di ） can forecast and estimate annual backsihing quantity in the Yangtze Estuary deepwater channel. The determined variation range of the vertical scale factor is -0.12 to 0.20. Thus, the variation range of recent years＇ annual backsilting quantity is 80.237 million m3 to 103.032 million m3, and the minimum quantity of backsilting is 6.580 million m3.