三门峡水库渭河下游库区近期水沙及河道冲淤分析

Analysis of recent water and sediment and river erosion and silting in the lower Weihe River of Sanmenxia Reservoir

为反映渭河防洪安全状况,依据2002-2020年实测水文泥沙、河道断面等资料,通过资料分析、数值计算等方法,分析了三门峡水库原型试验运用以来渭河下游的水沙系列特点和河道冲淤特征。研究得出:三门峡水库原型试验运用以来,渭河临潼站1000m/s^(3)以上洪峰的洪水量级和场次均呈减少趋势,咸阳、华县站水沙特点为平水枯沙系列;渭河下游累积冲刷泥沙2.663亿m^(3),累积淤积量由原型试验运用以前的逐步增大变为逐步减小;临潼站水沙条件是渭淤13-26断面间河段冲淤的重要影响因素,渭淤13断面以下河段历年累积淤积体变化与汛后潼关高程升降是正向关系,相关系数为0.82。提出了加强河道整治规划建设和现有工程管护防守、进一步降低潼关高程、加强现有水库综合效益发挥和水资源综合利用等建议。

In order to reflect the flood control situation of Weihe River,based on the data of hydrology,sediment and river topography from 2002 to 2020,through data analysis and numerical calculation and other methods,the characteristics of water and sediment variation,river erosion and deposition and influencing factors in the lower Weihe River of Sanmenxia Reservoir were analyzed.The results show that:The flood magnitude and field frequency above 1000 m^(3)/s at Lintong flood peak of Weihe River showed a decreasing trend since the prototype test;Xianyang and Huaxian Stations are normal water and dry sand series.The accumulative erosion sediment is 266.3 million m^(3) in the lower Weihe River,and the cumulative siltation amount changed from gradually increasing before the prototype test to gradually decreasing.The water and sediment condition of Lintong station is an important factor for the erosion and silting between sections 13 and 26.There is a positive relationship between the variation of accumulative siltation volume in Weiyu section below 13 and elevation rise and fall of Tongguan after flood seasons,and the correlation coefficient is 0.82.Some suggestions are put forward,such as to strengthen the planning and construction of river regulation and the management and defense of existing projects,further reduce the Tongguan elevation,and strengthen the comprehensive benefit of reservoirs and comprehensive utilization of water resources.