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本文采用统计分析和成因分析相结合的方法,考虑了降雨变化对减沙效益的影响,总结提出了减沙效益计算方法,估算了减沙效益的定量数值。近十几年来,黄河中上游水土保持及支流治理平均每年减沙3.253亿吨,减沙效益为22.8％,这种情况是在主要产沙区降雨量减少10—15％的情况下发生的,如遇降雨量增加,减沙效益也可能减小。对1971—1983年分析计算表明,河口镇以上拦沙、河道冲刷恢复、减沙之比为11:4:7;河龙区间及泾、洛、渭、汾均有不同程度的减沙作用。
In this paper, a combination of statistical analysis and cause analysis is taken into account. The influence of rainfall on the benefits of sediment reduction is considered. Finally, the calculation method of sediment reduction benefits and the quantitative values of sediment reduction benefits are estimated. In the past ten years, the average annual soil and water conservation and tributary governance in the middle and upper reaches of the Yellow River has decreased by 325.5 million tons per year on average, with a benefit of sediment reduction of 22.8%. This occurs when the rainfall in major sedimentary areas is reduced by 10-15% In case of rainfall increase, sediment reduction benefit may also be reduced. The analysis of 1971-1983 shows that sediment recovery and river erosion recovery above the mouth of the town are 11: 4: 7, and the river dragons and Jing, Luo, Wei and Fen all have different degrees of sediment reduction.