三峡水库的动防洪库容及防洪调度研究

发布时间：2018-05-07 18:54

本文选题：三峡水库 + 动库容　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：三峡水库的防洪能力对于长江中下游地区的防洪安全至关重要,而作为典型的河道型水库,在洪水调蓄过程中,充分考虑库区实际水面线以下的总库容(即动库容)对洪水的调节作用,能够更加科学地反映三峡水库对洪水的实际调蓄情况。三峡工程的设计防洪库容是在初步设计阶段按照静库容调洪方法确定,之后众多专家学者对其动库容调洪能力进行了研究,但尚无一致认同的结论。鉴于三峡工程的重要影响力,采用一维非恒定流水动力学模型,基于三峡正常运行期的监测数据和高精度地形数据,进一步研究明确三峡水库的实际防洪库容与防洪能力,对特大洪水条件下三峡的防洪调度意义重大。本文对基于圣维南方程的一维非恒定流水动力学模型进行研究,以偏危险的1954年洪水作为典型洪水进行放大,对三峡水库进行动库容调洪研究,分析其实际防洪能力,并且对特大洪水的防洪调度进行探讨,主要成果与结论如下:(1)建立了三峡库区一维非恒定流数学模型,对三峡水库进行动库容调洪计算。结合库区高精度的DEM数据,计算了库区沿程的支流河湾的库容曲线,对一维非恒定流模型进行了改进,修正了沿程支流河湾槽蓄作用对模型计算过程的影响,将水库天然库容完全纳入调洪计算中,提高了模型对实际洪水过程模拟的科学性。采用实测资料对模型进行了率定验证,结果表明模型精度较高,能够满足调洪演算的精度要求。(2)选择偏危险的1954年洪水过程作为典型洪水,放大得到百年一遇、千年一遇的设计洪水过程,根据三峡防洪调度规程分别对设计洪水进行调洪计算,得到动防洪库容值为224.46亿m3,与设计防洪库容值221.5亿m3基本一致,能够满足三峡工程初设的防洪任务。研究了糙率及水库地形概化对计算结果的影响,结果表明糙率引起的水面线误差对动防洪库容的影响很小,地形概化带来的误差对结果影响较大,必须予以考虑。(3)研究了沙市水位流量关系及荆江松滋、太平、藕池对洪水的分流作用。对于基于1954年洪水放大的千年一遇洪水过程的动库容调洪,设计了两种不同的防洪调度方式,保证沙市水位最高不超过45 m,从而保证荆江大堤的安全。调度方案一,坝前水位最高175 m,配合启用荆江分洪区,保证沙市水位安全;调度方案二,不启用分蓄洪区,抬高坝前水位(不超过校核洪水位),保证沙市水位安全。结果分析表明,在合适的调度规程下,在一些特大洪水情况下可以独立依靠三峡水库的调节完成防洪任务,避免启用分蓄洪区造成的损失。
[Abstract]:The flood control capacity of the three Gorges Reservoir is very important for the flood control safety in the middle and lower reaches of the Yangtze River. As a typical river reservoir, in the process of flood regulation and storage, Considering the total reservoir capacity (that is, moving reservoir capacity) below the actual water surface line in the reservoir area, it can more scientifically reflect the actual flood regulation and storage situation of the three Gorges Reservoir. The design flood control capacity of the three Gorges Project is determined according to the method of static capacity and flood control in the preliminary design stage. After that, many experts and scholars have studied the flood control capacity of the moving reservoir, but there is no unanimous conclusion. In view of the important influence of the three Gorges Project, a one-dimensional unsteady flow dynamic model is used to further study and determine the actual flood control capacity and flood control capacity of the three Gorges Reservoir based on the monitoring data and high-precision topographic data during the normal operation of the three Gorges Project. It is of great significance for flood control and operation of the three Gorges under the condition of super flood. In this paper, a one dimensional unsteady flow dynamic model based on San Venan equation is studied. With the partial dangerous 1954 flood as the typical flood, the dynamic reservoir capacity and flood regulation of the three Gorges Reservoir are studied, and the actual flood control capacity is analyzed. The main results and conclusions are as follows: 1) the one-dimensional unsteady flow mathematical model of the three Gorges reservoir area is established, and the flood control calculation of the three Gorges reservoir is carried out. Combined with the high precision DEM data of the reservoir area, the reservoir capacity curve of the tributaries along the reservoir area is calculated. The one-dimensional unsteady flow model is improved, and the influence of the channel storage along the tributary channel on the calculation process is corrected. The natural reservoir capacity of the reservoir is fully incorporated into the flood control calculation, which improves the scientific nature of the model for the simulation of the actual flood process. The accuracy of the model is high, and the model can meet the accuracy requirement of flood adjustment calculation. The model can select the partial dangerous 1954 flood process as the typical flood, and enlarge the model to get the one-in-a-century flood. According to the flood regulation of the three Gorges Project, the design flood control capacity of the dynamic flood reservoir is 22.446 billion m3, which is basically consistent with the designed flood control capacity value of 22.15 billion m ~ 3. It can meet the initial flood control task of the three Gorges Project. The effects of roughness and reservoir topography generalizability on the calculation results are studied. The results show that the surface line error caused by roughness has little effect on the dynamic flood control reservoir capacity, and the terrain generalization error has a great influence on the results. The relationship between water level and discharge and the diversion of Jingjiang, Taiping and lotus root ponds to flood are studied. In this paper, two different flood control modes are designed to ensure the maximum water level of sand city is not more than 45 m, so as to ensure the safety of Jingjiang embankment. First, the water level in front of the dam is up to 175 m, to ensure the water level safety of sand city with the use of Jingjiang flood diversion area, and the second plan is to raise the water level in front of the dam (not exceeding the check flood level) and ensure the safety of water level in sand city. The results show that the flood control task can be accomplished independently by the adjustment of the three Gorges reservoir under the proper regulation of operation and regulation, and the loss caused by the operation of the flood diversion and storage area can be avoided.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV697.13

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