【作者】 谢先红；

【导师】 杨金忠；

【作者基本信息】 武汉大学 ， 水利水电工程， 2005， 硕士

【摘要】 水库浸没是一个水库环境地质问题。建库后地下水位抬高引起附近地区环境和生态问题的经验教训,使浸没问题引起了人们重视。本论文以汉江兴隆水利枢纽和崔家营航电枢纽带来两岸浸没为背景,在总结前人研究成果的基础上,利用目前国际流行软件Visual Modflow建立数学模型,对水库浸没的规律及其防治措施进行了详细的探讨。其中介绍了Modflow基本原理及内部结构,阐述了排水边界、入渗补给边界和蒸发蒸腾边界的处理原则,以及减压井边界的实现。主要内容分三部分。 首先,建立概化的数学模型,模拟分析了两种土壤结构分别在表层土壤厚度、河水位、河弘深度等条件影响下,堤内地下水埋深的变化规律,在一定临界埋深的标准下,评定浸没程度,得出一些有意义的结论。 其次,根据浸没规律,在稳定流条件下,针对不同的土壤结构,研究排水沟（暗管）的排水降压功效,确定了合理的沟深和间距。当表层土壤渗透系数很小(小于10^-6cm/s)时,建议采用减压井来降低堤内水位。建立三维稳定流模型,研究了减压井间距、贯入度和井口高程对排水效果的影响,通过比较分析,确定减压井较优的控制参数。 最后,根据汉江中下游气象资料、地质条件,建立非稳定流模型,模拟水库蓄水,汉江水位升高后堤内的地下水位分布,对浸没程度进行预测。其中探讨了入渗系数和蒸发系数的确定,并为水库浸没的分析提供一般性的方法。并且,研究了非稳定流条件下排水沟和减压井的降压效果,利用水量均衡模块计算了排水效率。 数值模拟得出的结论为水库浸没的防控提供参考性意见。更多还原

【Abstract】 The immersion for reservoirs is a geological problem of reservoir environment. With the experiment and lessons from the effect of immersion on the ecosystem near the reservoir, the immersion has caused much attention. Taking the immersion in Xing Long Water conservancy project and Cui Jiaying shipping-dynamoelectric project in Hanjiang river as the background, the characteristics of immersion and methods for preventing immersion have been studied with the international popular software Visual Modflow to set up mathematics model on the basis of summarizing research results. The Modflow basic principle and inside structure were explained and the Drain, Recharge, Evapotranspiration and relief well boundary were illuminated in this thesis. The main content can be divided into three parts.First of all, the general mathematics model was established that was used to analyze the water table depth for two types of soil structure in the condition of different thickness of top layer, river level and depth of river bed. The immersion degree could be evaluated with the criterion of pre-defined critical water table depth and significative conclusions were drawn from the simulationSecondly, according to the immersion characteristics, the drainage effect and reasonable distance and depth of drainage ditches （including subsurface tube） were discussed to different soil structure with steady state flow. The relief well is commended when the hydraulic conductivity of top layer soil is less than 10^-6cm/s. Three dimensional steady state model was adopted to simulate the distance, the proportion of filter length and the elevation of well head. The relative rational control parameters of relief wells were gained through comparative analysis.At last, in term with the meteorological condition, geological condition of midstream and downstream of the Hanjiang River, a transient flow model was established to predict the distribution of water table and the immersion degree after the hoisting of river level,and In this course, the determination of recharge and evaporation coefficients were discussed in detail. These methods can serve for immersion analysis under the similar condition. The drainage and depressurization results of drainage ditches and relief wells were simulated with transient flow model, and the drainage efficiency was calculated by transferring Zone Budget module.In a word, the conclusions from the numerical simulation offer the reference suggestion for prevention and control of the immersion for reservoirs.更多还原