三门峡水库淤积及潼关高程的滞后响应

Delayed Response of Tongguan's elevation to the sedimentation in Sanmenxia Reservoir

研究了三门峡水库淤积和潼关高程随坝前水位和来水条件变化的响应规律,分析了库区河床演变的滞后现象。发现水库的累计淤积量和潼关高程,不仅受当年水沙条件和坝前水位的影响,而且通过前期边界条件,还受过去若干年内的水沙条件和坝前水位的影响。表现在潼关高程的升降变化较库区泥沙淤积滞后大约2年,库区累计淤积量与5年叠加坝前水位关系密切,潼关高程与6年叠加入库水量之间具有较好的相关关系,以及潼段比降与7年移动平均坝前水位之间的关系最好。

This paper presents a study of the reservoir sedimentation and the variation of Tongguan＇ s elevation in response to changes in flow and pool level of the Sanmenxia dam. The hysteresis phenomenon occured in the fluvial processes of the reservoir was thoroughly studied. Research found that the accumulated sediment deposition and the elevation of Tongguan were affected not only by the current year＇ s flow and pool level conditions, but also by the previous years＇ flow and pool level conditions. This was demonstrated by the 2 years of time delay in Tongguan＇ s elevation compared with the sediment deposition in the reservoir area downstream Tongguan. And the sediment deposition in the reservoir area was closely related to the 5 years＇ superimposed pool level. In addition, under the operational conditions of controlled release adopted since 1974, the elevation of Tongguan was closely related to the six continuous years＇ weighted-average runoff. Also the channel bed slope from Tongguan to Guduo is related to the 7 years＇ moving average pool level.