黄河小北干流冲淤与水沙响应关系分析

Analysis of the Relationship Between Scouring and Silting and Response of Water and Sediment in Xiaobeiganliu Reach of the Yellow River

依据实测大断面资料,给出了1974年以来黄河小北干流不同时段、不同河段的沿程冲淤量,分析了2003年以来该河段持续冲刷的原因,并对不同水沙搭配组合与小北干流冲淤量的响应关系进行了分析。结果表明:①1974年三门峡水库采用蓄清排浑运用方式以来,黄河小北干流的冲淤变化主要受来水来沙条件影响,基本保持非汛期冲刷、汛期淤积的特点。2003—2016年受上游汛期来沙量大幅减小的影响,沿程各河段汛期淤积量明显减小,在非汛期冲刷量减小不多的情况下,运用年各河段均为持续冲刷。②汛期水沙搭配组合中含沙量对冲淤量的影响程度更显著,运用年内水沙搭配组合中含沙量和流量对冲淤量的影响程度相当。

This paper gave the amount of erosion and sedimentation delivery in different periods and different reaches in Xiaobeiganliu reach since 1974 based on measured data of large sections and analyzed the reason of increasing erosion in this reach since 2003 and response relation between different water and sediment collocation and the amount of erosion and sedimentation in Xiaobeiganliu reach. The results show that: a) incoming water and sediment has mainly effected on the change of erosion and sedimentation in Xiaobeiganliu reach, which basically maintains the erosion in nonflood season and sedimentation in flood seasons since the operation mode of storing clear water and releasing muddy water has been applied in Sanmenxia Reservoir since 1974. Each reach is continuous erosion in a year because of significant decreasing amount of sedimentation which affected by significant decreasing of upstream incoming sedimentation in flood season from 2003 to 2016 as well as few decreasing of erosion in nonflood season and;b) sediment concentration has more significant effect on the amount of erosion and sedimentation in water and sediment collocation in flood season and sediment concentration and flow has equal effect on the amount of erosion and sedimentation of water and sediment collocation in a year.