渭河下游输沙水量及输水输沙通道研究

发布时间：2018-05-01 18:55

本文选题：渭河下游 + 水沙关系　；参考：《中国水利水电科学研究院》2014年硕士论文

【摘要】：渭河是黄河的重要支流,也是黄河主要的水沙来源之一,同时作为一条多沙河流,引起学者的广泛关注。三门峡水库修建以来,由于潼关高程的相应抬升,渭河各河段出现不同程度的变化,尤其是下游河段,出现较为严重的淤积,这使得渭河水沙问题更为突出。近年来,潼关高程逐渐稳定,河道基本回到平衡状态,但水少沙多问题加剧,沿程用水量激增,各方面问题依然存在。找寻新平衡条件下,渭河输沙用水与生产生活用水间的平衡点以保证渭河河道的稳定,已经成为新的研究方向。本文归纳之前学者的研究,运用泥沙动力学、河床演变学等基础知识,结合渭河特有的水沙关系与变化趋势,在潼关高程近期相对稳定的条件下,以研究渭河下游输沙水量和未来河道输水输沙规模为目标。主要研究内容及研究结论归纳如下：1.通过对1950～2009年来水来沙情况、水沙变化及特征、流域产流产沙区域分布、年内水沙分配、实测各流量级等多方面分析,得到以下主要认识：(1)渭河下游为黄河流域的水少沙多区,具有明显的水沙异源特点。来水来沙过程年际间变化大,1960年代以来水沙量呈总体减少趋势,2000年以来沙量明显减少。年内水沙分配不均匀,主要来水来沙过程集中于汛期,2000年以来水量向汛期转移,来沙向汛期高度集中,咸阳站、华县站和张家山站三站汛期沙量占比均达到97%以上。(2)泾河来沙多导致渭河下游水沙关系极不协调,华县站多年平均和汛期平均来沙系数分别为0.217kg/s.m6和0.178kg/s.m6,比花园口站大一个数量级,1986-2002年水沙关系最差；2003年以来咸阳水沙的搭配有所好转,但非汛期水沙搭配恶化。(3)渭河下游出现天数最多的流量级为0-500m3/s,0～000m3/s为主要的输水输沙流量级,1000-1500m3/s流量级的输沙也占了较大比例,大于1500m3/s的各流量级所带水沙量比例不大。2003年后0-500m3/s流量级输沙比例呈明显增大的趋势。2.分析了三门峡水库运用以来不同时期渭河下游的淤积特点及河道萎缩特征,得到：(1)渭河下游自三门峡水库运行以来,渭河下游淤积加重,累积淤积量12.86亿m3；受三门峡工程不同运用方式和水沙条件的影响,渭河下游冲淤过程阶段性明显,1960-1973年潼关高程迅速抬升,渭河下游河段大量淤积；1973年对三门峡进行改建,潼关高程暂时得到控制,渭河下游临潼至华县段少量冲刷,其余各段均出现少量淤积；1986-2002年径流明显减少,导致潼关高程继续抬升,各河段均以淤积为主,多数表现为汛期淤积非汛期冲刷；2003年三门峡水库再次改变运行方式,2003年和2005年水沙有利,潼关高程出现小幅下降趋势,渭河下游总体表现为微冲。(2)2003年以前,渭河下游河段明显萎缩,主要表现在主槽过流能力减少,河道横断面呈现缩窄趋势,交口以下河段深泓点抬升等。通过对三门峡水库的调整,2003年后平滩流量有所回升,逐步稳定在2500m3/s左右,说明主槽萎缩趋势有所缓和。3.在对现有输沙水量计算方法进行了全面总结的基础上,以1973-2009年水沙系列为依据,通过曲线拟合或半经验公式推导得到资料分析法、冲淤修正法和不平衡输沙法三种适合渭河下游输沙水量计算方法。以此计算了1973-2009年实际冲淤量和不同允许淤积量下的渭河下游输沙水量,三种方法计算结果有一定差异,取平均值的结果表明：在实际淤积情况下,华县站的年输沙水量为52.45亿m3,4.2亿m3的水未用于输沙。若要使渭河下游的年均淤积量分别减少到0.1亿t、0.05亿t和0亿t,华县站年水量需分别达到60.23亿m3、65.1亿m3和69.96亿m3。4.建立了包括渭河下游和三门峡库区的水沙数学模型,经实测资料率定和验证后进行了平水平沙系列、前期水沙偏丰系列和前期偏枯60年水沙系列下的渭河下游淤积量、淤积过程及以平滩流量为指标的输水输沙通道规模计算,计算结果表明,渭河下游未来仍将呈累计淤积状态,以滩地淤积为主,前10年全河段累计淤积1.90亿t,后50年各方案淤积11.08亿t-12.37亿t；未来10年,渭河下游的输水输沙通道临潼-华县在2300m3/s,华县以下能维持在2700m3/s。长期来看,临潼-华县平滩流量1800m3/s以下,华县以下河段在2000m3/s左右。
[Abstract]:Weihe is an important tributary of the Yellow River. It is also one of the main sources of water and sand in the Yellow River. At the same time, as a multi sand river, it attracts extensive attention of scholars. Since the construction of the Sanmenxia reservoir, due to the corresponding elevation of the Tongguan elevation, the different degrees of change in each section of the Weihe River appear, especially the lower reaches of the river, which makes the Wei River more serious. In recent years, the river sediment problem is more prominent. In recent years, the Tongguan elevation is gradually stable, the river is basically back to the state of balance, but the problem of water less sand and sand intensifies, the water consumption along the path is increasing, and the problems still exist in all aspects. In search of the new balance conditions, the balance point between the water supply and the production and living water in Weihe is to ensure the stability of the Weihe River, which has become new. This article summarizes the previous scholars' research, using the basic knowledge of sediment dynamics, river bed evolution and other basic knowledge, combined with the specific water and sediment relationship and trend of change in Weihe, and under the relatively stable conditions of the Tongguan elevation in the near future, the main research content and Research on the sediment transport in the lower reaches of the lower reaches of the Weihe and the scale of the water transport and sediment transport in the river channel in the future. The following conclusions are summed up as follows: 1. through the analysis of water and sediment in the 1950~2009 years, the change and characteristics of water and sediment, the distribution of runoff and sediment in the basin, the distribution of water and sediment in the year, the actual flow level, and so on, the following main understanding is obtained: (1) the lower reaches of the lower reaches of Weihe are the less sand and sandy area of the the Yellow River River Basin, which has obvious characteristics of water and sand sources. Since 1960s, the amount of water and sand has decreased since the year of 1960s, and the sand amount has decreased obviously since 2000. The distribution of sand and sediment is uneven in 2000. The main flow and sediment process is concentrated in the flood season. Since 2000, the water flow is transferred to the flood season, the sediment is highly concentrated in the flood season, and the sand amount of the three stations in the XianYang Railway Station, the Hua county station and the Zhangjia mountain station are all reached. To 97% above 97%. (2) the water and sediment relations in the lower reaches of Weihe are very incongruous. The average sediment coefficient of the years and the flood season of the Hua county station is 0.217kg/s.m6 and 0.178kg/s.m6 respectively, which is one order of magnitude larger than the garden gate station, and the worst water sediment relationship in 1986-2002 years. Since 2003, the collocation of water and sediment in Xianyang has improved, but the water and sediment collocation in non flood season (3) the flow grade of the largest number of days in the lower reaches of Weihe is 0-500m3/s, 0 ~ 000m3/s is the main flow grade of water transport and sediment transport, and the sediment transport in 1000-1500m3/s flow level is also a large proportion. The proportion of water and sediment with the flow level of each level larger than 1500m3/s is not much higher than that of 0-500m3/s flow grade after.2003 years, and the.2. analysis is three. The siltation characteristics and river shrinkage characteristics of the lower reaches of Weihe in different periods since the application of the menxia reservoir have been obtained. (1) since the lower reaches of Weihe are running from the Sanmenxia reservoir, the sedimentation of the lower reaches of the Weihe is aggravated and the accumulated silt is 1 billion 286 million m3; under the influence of the different application ways and the water and sand conditions of the Sanmenxia project, the process of erosion and siltation in the lower reaches of the Weihe is obvious, 1960- In 1973, Tongguan elevation was raised rapidly and the lower reaches of Weihe were silted up in large quantities; in 1973, Sanmenxia was rebuilt, Tongguan height was temporarily controlled, a small amount of scour in Lintong to Hua county of the lower reaches of Weihe, and a small amount of siltation in the rest of the other sections; the runoff of the 1986-2002 years decreased significantly, resulting in the continued uplift of Tongguan, and siltation in each of the sections of the river. Most of the performance is the flood period silting in non flood season. In 2003, the Sanmenxia reservoir changed the operation mode again. In 2003 and 2005, the water and sediment were favorable, the Tongguan elevation declined slightly, and the lower reaches of the Weihe were micro flushing. (2) before 2003, the lower reaches of the Weihe decreased obviously, mainly in the decrease of the main channel overflow capacity and the cross section of the river channel. With the adjustment of the Sanmenxia reservoir, the Sanmenxia reservoir was adjusted, and the flat rate of flat beach was recovered to a certain extent after 2003, and gradually stabilized at around 2500m3/s, indicating that the main trough atrophy trend was eased by.3., based on the total sum of the existing methods for calculating the current sediment water quantity, based on the 1973-2009 year water and sand series. Through the curve fitting or the semi empirical formula derivation, the data analysis method, the erosion and siltation correction method and the unbalanced sediment transport method are three suitable methods for the calculation of the sediment transport in the lower reaches of Weihe. In order to calculate the 1973-2009 years actual erosion and siltation and the different allowable silt, the amount of water transport in the lower reaches of the lower reaches of the Weihe is different and the average value is taken. The results show that, under the actual siltation, the annual sediment discharge of 5 billion 245 million m3,4.2 million m3 is not used for sediment transport. If the annual average siltation in the lower reaches of the Weihe is reduced to 10 million T, 5 million T and 0 billion T, the annual water capacity of the Hua county station should be 6 billion 23 million m3,65.1 billion m3 and 6 billion 996 million m3.4., respectively, including the lower Weihe and three gates. The mathematical model of water and sediment in the gorge reservoir area is determined and verified by the measured data rate and verification. The sediment volume in the lower reaches of the Weihe River, the sedimentation process in the lower reaches of the early water sand partial and the earlier 60 years of water and sand series, and the calculation of the sediment transport channel scale with the flow of flat beach as the index. The calculation results show that the future of the lower reaches of Weihe will still be tired. In the first 10 years, the total siltation is 190 million T accumulated in the whole river section in the first 10 years, and 1 billion 108 million t-12.37 billion T in the last 50 years. In the next 10 years, the water transport and sediment transport channel in the lower reaches of Weihe is in the Lintong Hua county, which can be maintained in 2700m3/s. for a long time, and the flow rate of the Lintong Hua county flat beach is below 1800m3/s, and the lower reaches of the Hua county are 2 About 000m3/s.

【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV14

【参考文献】