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一、水土保持工程的作用时间问题 分析水土保持工程的拦沙作用,首先要弄清水保工程的发展过程,抓住水保工程引起入黄沙量有明显变化的起始时间,才能比较准确地算出水保工程的拦沙效益。过去确定水保工程的拦沙作用时间,有的从1958年开始,把短时期的拦沙效益分配到较长的时段上,这必然会低估水保工程的年平均拦沙效益;有的根据三门峡水库的起用时间(1960年)和改建后起用时间(1974年),把下游河道冲淤变化的系列移到中游计算水保工程的拦沙效益上,这样
First, the role of soil and water conservation project Time Analysis of the role of soil and water conservation efforts to stop the sand, first of all to understand the development process of water and soil conservation projects, water and soil conservation project to seize the yellow sand caused significant change in the starting time to more accurately Calculate the water conservancy project of the sand blocking benefits. In the past to determine the water and soil conservation project of the role of sand blocking, and some from 1958 onwards, the short-term benefits of silt distribution to a longer period of time, which inevitably underestimated the water conservation project average annual sediment recovery benefits; some based on Sanmenxia reservoir starting time (1960) and after the renovation of the starting time (1974), the lower reaches of the river scouring and silting changes in the series moved to the midstream calculation of water conservancy project of sediment recovery benefits, so