基于砂箱实验的滨海含水层管理数值模拟研究

发布时间：2018-05-12 13:45

本文选题：滨海含水层 + 海水入侵　；参考：《烟台大学》2017年硕士论文

【摘要】：滨海含水层是滨海地区淡水资源的主要来源,滨海含水层的管理对于滨海地区社会经济的发展具有重要意义。海水入侵作为滨海地区影响最为广泛的自然灾害,对于滨海含水层的地下水资源具有重要影响。本文通过构建二维砂箱模型,研究抽取地下咸水对于海水入侵咸淡水界面运移的影响,并通过数值模拟的方法研究滨海含水层地下水的优化开采方式对海水入侵的防治应用,提出滨海含水层多目标管理系统,为滨海含水层管理提出合理建议。通过构建室内砂箱物理模型并结合着色技术,分析不同抽咸强度和布井方式下海水入侵咸淡水界面运移规律以及地下水流场演变机制,研究不同情境下抽取咸水对于海水入侵的防治效果。结果表明:地下水流场受抽取咸水的强度和布井方式影响,可通过加大咸水抽取强度、优化布井方式,实现抽咸防治海水入侵的最佳效果。固定咸水抽取强度时,远离咸淡水界面进行的叠加井抽水与单井抽水效果相比,并不具备优越性;在海水入侵界面以下咸水体上部抽取咸水,可防止抽咸过程中海水入侵界面向内陆移动,在海水入侵界面近趾端处抽取咸水可以使海水楔趾端更快向海水区回退;保持一定的咸水抽取强度时,在海水入侵界面以下咸水体上部与趾端位置处进行分散式布井,可以达到整体修复滨海含水层的效果。通过构建抽取地下咸水防治海水入侵的数值模型,模拟分析相同布井方式下不同抽咸强度防治海水入侵的效果,结果表明:加大抽咸强度后,抽取地下咸水可更快达到防治效果。但是,达到一定的咸水开采强度后,咸水开采达到一定高强度后,淡水和咸水会在井内混合,形成逼近抽水井的咸淡水楔形界面。构建包括滨海含水层数据库子系统、评价模型子系统、数值模拟子系统、防治技术子系统、管理方案子系统等多个子系统的滨海含水层多目标管理系统,并提出滨海含水层管理的决策和建议,为滨海含水层的多目标管理提供技术支持。
[Abstract]:Coastal aquifer is the main source of freshwater resources in coastal area, and the management of coastal aquifer is of great significance to the development of social economy in coastal area. As the most extensive natural disaster in coastal area, seawater intrusion plays an important role in groundwater resources of littoral aquifer. In this paper, a two-dimensional sand tank model is constructed to study the effect of extracting salt water on the interface migration of salt and fresh water in seawater intrusion, and to study the application of optimal exploitation of groundwater in coastal aquifer to the prevention and treatment of seawater intrusion by numerical simulation. The multi-objective management system of coastal aquifer is put forward, and some reasonable suggestions for the management of coastal aquifer are put forward. By building indoor sand tank physical model and combining coloring technology, this paper analyzes the migration law of salt-fresh water interface and the evolution mechanism of groundwater flow field under different salinity intensity and well layout mode. To study the prevention and cure effect of salt water extraction on seawater invasion in different situations. The results show that the groundwater flow field is affected by the strength of the extracted salt water and the pattern of well layout. The best effect of brackish water extraction and prevention of seawater intrusion can be achieved by increasing the extraction intensity of salt water and optimizing the pattern of well layout. When the extraction strength of fixed salt water is fixed, the superimposed well pumping away from the interface of salt and fresh water is not superior to that of single well pumping, and the salt water is extracted from the upper part of the salt water body below the salt water invasion interface. It can prevent the seawater intrusion interface from moving inland during the process of brackish drainage. The extraction of salt water near the toe end of the seawater intrusion interface can make the wedge end of the seawater recede back to the sea water area more quickly, and when the salt water extraction intensity is maintained, a certain amount of salt water extraction intensity can be maintained. The effect of restoring littoral aquifer can be achieved by distributed well arrangement at the upper part and toe end of salt water body below the interface of seawater intrusion. By constructing a numerical model of salt water extraction to prevent seawater intrusion, the effects of different brackish intensity on seawater intrusion prevention under the same well distribution mode are simulated and analyzed. The results show that: after increasing salt water intensity, The control effect can be achieved more quickly by extracting underground salt water. However, when the exploitation intensity of salt water reaches a certain degree, the fresh water and salt water will mix in the well and form a wedge interface of salt and fresh water approaching to the pumping well after the exploitation of salt water reaches a certain high intensity. The multi-objective management system of coastal aquifer is constructed, which includes database subsystem, evaluation model subsystem, numerical simulation subsystem, prevention and control subsystem, management scheme subsystem and so on. The decision-making and suggestion of coastal aquifer management are put forward to provide technical support for multi-objective management of littoral aquifer.
【学位授予单位】：烟台大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P641.8;P731.2

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