渭河下游河道冲淤演变趋势数值模拟研究

发布时间：2018-04-24 00:39

本文选题：数学模型 + 渭河下游　；参考：《西安理工大学》2017年硕士论文

【摘要】：渭河流域综合治理工程实施后,必然对渭河的来水来沙等造成影响。本文采用数值模拟的方法研究渭河下游河道冲淤演变趋势,为渭河流域后续治理及管理提供技术支撑,具有重要的现实意义。本文对泥沙数学模型中的一些如动床糙率、非均匀沙沉速等问题进行了探讨,并在此基础上对现有的泥沙数学模型进行了完善。依据各相关水文站的实测资料,对渭河下游河段和黄河龙门～潼关河段的水沙特性及冲淤特性进行了简要分析。采用1969～1995年实测资料对模型的适应性、计算参数等进行了率定,并用2008～2012年实测资料对模型进行了验证。计算结果可知,各河段的河道计算冲淤量值与实测冲淤量值基本相符。利用验证后的数学模型对3种不同水沙系列情况下渭河下游河道的冲淤过程及其冲淤对渭河下游不同流量级洪水位的影响进行了模拟计算,并对计算结果进行了分析。主要结论为:(1)3种不同水沙系列情况下,除渭拦～渭淤1河段为累计淤积外,其余河段均为累计冲刷;丰水丰沙、枯水枯沙及现状水沙系列情况下,渭河下游河段总冲刷量分别为0.838亿m3、1.357亿m3及1.671亿m3;即从总冲刷量来看,渭河下游河道将以冲刷为主要趋势。(2)渭淤1～10河段、渭淤10～26河段、渭淤26～37河段总冲刷量占渭河下游全河段总冲刷量的比例,丰水丰沙系列情况下分别为34.99%、5.53%、59.48%;枯水枯沙系列情况下分别为23.86%、29.70%、46.43%;现状水沙系列情况下分别为27.78%、28.78%、43.43%;即从冲刷量的空间分布来看,渭河下游河道冲刷量主要分布在渭淤26～37河段。(3)从渭河下游河段累计冲淤量随时间的变化来看,丰水丰沙系列除第4年～第6年发生累计性淤积外,其余年份均发生累计性冲刷;而枯水枯沙及现状水沙系列计算年份内均为累计性冲刷过程。(4)不同水沙系列条件下,渭河下游不同河段冲淤情况不同,洪水位升降幅度也有所不同;因渭淤26～37河段冲刷量最大,故其不同流量级洪水位下降幅度亦最大。
[Abstract]:After the comprehensive control project of Weihe River Basin is carried out, it will inevitably affect the coming water and sediment of Weihe River. In this paper, the method of numerical simulation is used to study the trend of erosion and siltation in the lower reaches of the Weihe River. It is of great practical significance to provide technical support for the subsequent management and management of the Weihe River Basin. In this paper, some problems in sediment mathematical models such as the roughness of moving bed and the velocity of non-uniform sediment settlement are discussed, and the existing mathematical models of sediment are improved. Based on the measured data of various hydrological stations, the characteristics of water and sediment in the lower reaches of the Weihe River and the Longmen to Tongguan reach of the Yellow River are analyzed briefly. The adaptability and calculation parameters of the model are determined by using the measured data from 1969 to 1995, and the model is verified by the measured data from 2008 to 2012. The calculated results show that the calculated values of scour and siltation are in good agreement with the measured values. By using the verified mathematical model, the scour and deposition process of the lower Weihe River and the influence of the erosion and deposition on the flood water level of different discharge levels in the lower reaches of the Weihe River are simulated and calculated under three different water and sediment series, and the calculated results are analyzed. The main conclusions are as follows: in the case of three different water and sediment series, except for the accumulative siltation in the Wei bar and Wei silt reach, the other reaches are all accumulated scour, and in the case of abundant water and sand, low water and dry sand and present water and sediment series, The total scour amount of the lower reaches of the Weihe River is 83.8 million m3, 135.7 million m3 and 167.1 million m3 respectively. The proportion of total scour to the total scour in the lower reaches of the Weihe River is 34.995.535.53 in the Fengshui Fengsha series; 23.866.86 in the dry water and dry sand series; and 27.78 28.780.43.43in the present water and sand series respectively; that is, from the perspective of the spatial distribution of the scour volume, The amount of erosion in the lower reaches of Weihe River is mainly distributed in section 2637 of Weihe River.) from the time variation of the accumulated amount of scour and deposition in the lower reaches of Weihe River, the accumulation of sediment accumulation in the series of abundant water and sand occurred in the other years except for the 4th year to the sixth year. Under the conditions of different water and sediment series, different erosion and siltation conditions in the lower reaches of the Weihe River, the fluctuation of flood water level is also different, because the erosion amount of Wei26silt No. 37 reaches is the largest. Therefore, its different discharge levels of flood water level decline range is also the largest.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV147

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