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利用河道断面测量数据计算了1960~1990年渭河下游河槽和滩地冲淤量及其分布的时空变化,分析了变化发生的原因。结果表明:1960~1990年间共淤积泥沙8.88×108m3,且泥沙主要分布在渭淤11断面(WY11)以下河段。滩地淤积量是河槽的1.83倍,滩地冲淤过程以1968年和1982年为转折点分为3个阶段,依次经历了快速淤积、缓慢淤积和侵蚀3个过程。其中淤积以滩面垂向加积为主,侵蚀主要表现为河岸侵蚀后退或坍塌。河槽以1969年为转折点分为快速淤积和轻微淤积(冲刷淤积交替)两个阶段。年内滩地和河槽在汛期整体上淤积,非汛期滩地侵蚀(主要以河道侧向侵蚀形式),而河槽表现为微淤,滩地在汛期堆积和非汛期侵蚀的倾向较河槽明显。三门峡水库在蓄水拦沙(1960年9月~1962年3月)和滞洪排沙(1962年3月~1973年10月)阶段,泥沙淤积上延到渭淤17(WY17)和渭淤27断面(WY27)间河段;实行蓄清排浑(1973年11月~1990年)后溯源淤积大为减弱,淤积未再上延,河道冲淤趋向于平衡。潼关高程是影响河槽和滩地泥沙淤积和释放的主要原因之一。此外,滩地的冲淤量与当年汛期来沙量相关性最高,而河槽冲淤量与当年汛期径流量相关性最高。
The spatial and temporal variations of scour and silting volume and its distribution in the lower reaches of the Weihe River from 1960 to 1990 were calculated using the cross-section data of the river course. The causes of the changes were analyzed. The results showed that silt sediment was 8.88 × 108m3 between 1960 and 1990, and the sediment was mainly distributed in the lower reaches of WY11 section. The sedimentation of the beach is 1.83 times that of the river channel. The scour and deposition process of the beach land is divided into 3 stages with the turning points of 1968 and 1982, followed by three processes of rapid deposition, slow deposition and erosion. Among them, siltation was dominated by vertical accretion of beach surface, and erosion was mainly manifested as receding or collapsing of riverbank erosion. The trough in 1969 as a turning point is divided into rapid siltation and slight siltation (erosion siltation alternation) two stages. During the year, floodplain and fluvial channel were generally accumulated in flood season, and erosion in floodplain during non-flood season (mainly in the form of lateral erosion of river channel). However, the fluvial channel showed slight siltation. The tendency of beachland in flood season accumulation and non-flood season was more obvious than that in fluvial channel. Sanmenxia reservoir in the sediment storage (September 1960 ~ March 1962) and detention flood sediment (March 1962 ~ October 1973) stage, the silt up to Wei silt 17 (WY17) and Wei silt 27 river section (WY27). After traceability and sedimentation (from November 1973 to 1990, 1973), the sedimentation of traceability was greatly weakened, and siltation was no longer delayed. The erosion and deposition in the river channels tended to balance. Tongguan elevation is one of the main reasons that affect the siltation and release of sediments in the river channel and beach. In addition, the amount of scouring and silting on the beachland has the highest correlation with the amount of sediment in the flood season of the current year, and the correlation between the amount of scouring and silting in the river channel and the flood season in that year is the highest.