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基于实测资料分析,根据三门峡水库建成后不同运行模式,分1961-1973年、1974-1990年和1991-2001年三个时间分析了渭河下游河道泥沙冲淤变化特点、河道比降演变规律以及河道泥沙淤积对河床比降的影响关系。结果表明:泥沙淤积量主要在临潼以下河段产生,河道泥沙冲淤由建库运行后的溯源淤积变化到冲淤动态平衡,但进入20世纪90年代以来,出现了渭河下游全河段的淤积的趋势;咸阳-临潼段的河床比降在1961-1973年间呈现出显著的逐年增加的趋势,但之后由1974-1990年间的增加趋势变缓变化到1991-2001年间减小趋势,而临潼-华县段的河床比降在三个时期均呈现逐年减小的趋势,在1961-1973年减小幅度最大,1974-1990年减小趋势最缓;河床比降与河道泥沙累计淤积量具有较好的负相关性。在三门峡水库蓄清排浑运用之前的1960-1973间及其之后的1990年以来,河道泥沙淤积造成河床比降下降的影响作用尤为显著。
Based on the measured data, according to the different operation modes of the Sanmenxia Reservoir after completion, the change characteristics of sediment deposition and deposition in the lower reaches of the Weihe River from 1961 to 1973, 1974 to 1990 and from 1991 to 2001 were analyzed. Influence of river sediment deposition on river bed slope. The results show that sediment deposition mainly occurs in the lower reach of Lintong River. The sediment deposition in the river channel changes from traceability to scouring and silting dynamic balance after the reservoir operation, but since the 1990s, . The river bed slope of Xianyang-Lintong section shows a significant increasing trend year by year from 1961 to 1973, but then decreases slowly from 1974 to 1990, and decreases from 1991 to 2001 The ratio of river bed in Lintong and Huaxian sections decreased year by year in three periods, decreasing most in 1961-1973 and decreasing in 1974-1990. The amount has a good negative correlation. In the period from 1960 to 1973 after the Sanmenxia reservoir was drained and drained, the influence of river sedimentation on the riverbed drop was especially significant since 1990 and beyond.