【作者】 卜英；

【导师】 徐国宾；

【作者基本信息】 天津大学 ， 水利水电工程， 2010， 硕士

【摘要】 三峡水库蓄水运行后干支流水文情势发生巨大变化,库区支流水体水质恶化,非汛期支流的局部水域易暴发“水华”现象。其主要原因是蓄水后支流由天然状态的流速1～2m/s变成几乎静止,水体紊动和水流流速的降低造成营养盐的聚集和藻类快速生长。而三峡电站非汛期采用调峰运行,电站调峰有利于干、支流水体的交换,增大水体紊动和水流流速,从而为改变支流的水质提供了新契机。传统研究多采取一维水动力模型,其数值模拟结果不能反映深水水库显著的垂向水动力特性。基于此,开展不同调度方案下三峡库区垂向二维水动力模型研究。具体研究内容和结论如下:(1)分析CE-QUAL-W2垂向二维水动力学和水质模型的基本原理、功能及限制条件和模型的优点。采用CE-QUAL-W2垂向二维水动力学和水质模型,建立了三峡库区垂向二维水动力模拟模型。(2)模拟分析了日调峰运行与日不调峰均匀泄流运以及不同调峰幅度下的库区水动力过程。数据表明:与不调峰运行方式相比,调峰运行方式提高了支流水体流速,加强了干支流的水体交换和掺混。而且随着调峰幅度的增加,水体交换量和交换速度同步提高。(3)模拟分析了相同日运行方式和不同典型库水位条件下的三峡库区水动力过程。数据表明:随着库水位的升高,支流水体流速增大,干支流水体交换量增大,有利于稀释支流污染物浓度。(4)模拟了相同日运行方式和不同水位蓄放方式下的三峡库区水动力过程。数据表明:与水位不变运行方式相比,水位蓄放方式缩短了水体置换时间短,加强了干支流水体交换,有利于支流水质的改善。而且在先蓄后放方式下,干支流水体掺混最强。更多还原

【Abstract】 After the Three Gorges Reservoir tributaries hydrological run a big change in reservoir tributary water quality deterioration, non-flood prone tributaries of the local waters outbreak "bloom" phenomenon. Because the high water level results in the decreases of the flow velocity and turbulence, which leads to the enrichment of nutrient and fast growth of algae. While in the non-flood season, the Three Gorges Power Station will be in peak load operation, which will benefit the water exchange between main stream and tributaries and increase the water turbulence and velocity. Therefore, the peak load operation will provide a new way to improve the water quality of the tributaries. One-dimensional hydrodynamic model is used in traditional research, the numerical simulation result can not reflect the deep reservoir significant vertical hydrodynamic characteristic. Based on this, study on a two-dimensional,laterally averaged, hydrodynamic model to three-gorge reservoir under different scheduling mode is necessary.Specific content and conclusion of the study are as follows:(1) Analysis of the CE-QUAL-W2 vertical two-dimensional hydrodynamic and water quality model’s basic principles, functions, restrictions and benefits of the model. This article use CE-QUAL-W2 vertical two-dimensional hydrodynamic and water quality model simulate to a two-dimensional,laterally averaged, hydrodynamic model to three-gorge reservoir(2) The simulation analysis with no load uniform load operation discharge operation and the peak amplitude under different water reservoir. Data shows that compared with no load operation mode, the peak load regulating operation ways to improve the water velocity, strengthen the tributary of the uprising water exchange and mixing. But with the peak amplitude increase, water exchange volume and exchange synchronous speed is increased.(3) The simulation analysis water dynamic process of the three gorges reservoir under the condition operation mode and the same in different typical water. Data shows that, with the increase of water, the water velocity increasing, the tributary exchange volume uprising, to dilute the tributary pollutant concentration.(4) Simulate water dynamic process of three gorges reservoir under the same operation mode and different levels of regenerative. Data shows that compared with constant water level, water storage operation to shorten the water displacement put short time, strengthen the tributary, increased water exchange separately, improved water quality. And after the first storage, the tributaries water exchange is the strongest.更多还原