【作者】 吴亚娜；

【导师】 王文科；

【作者基本信息】 长安大学 ， 水文学及水资源， 2011， 硕士

【摘要】 开展傍河抽水驱动下饱和非饱和带中河流污染对地下水水质的影响研究,对发展与创新河床下溶质在含水层中的运移理论和研究方法等具有十分重要的理论和实际意义。本文以河流与地下水演化关系为主线,采用室内物理模拟实验与数值模拟相结合的方法,研究保守性物质NaCl与非保守性有机污染物硝基苯在河流-悬挂饱水带-包气带-地下水系统中的转化规律,构建对流、弥散、吸附共同作用下水流与溶质运移的耦合模型,定量描述河流污染对地下水的影响程度。本文得到的结论有：1、在无水动力驱动情况下的纯弥散作用下,随着时间的增加,溶质运移规律明显表现出重力分异现象,这个结论表明研究无水动力驱动下的溶质运移中重力作用是一个不可忽略的因素。2、傍河抽水条件下,当河流与地下水具有统一浸润曲线时(A-160-130方案,实验总时间为2265min),随着抽水强度的增大,溶质运移速度增大；河流与地下水临界“脱节”时的溶质运移速度最大(C-160-90方案,实验总时间为765min)；当河流与地下水“脱节”之后,由于包气带的范围增大,溶质运移速度略有减小(F-160-40方案,实验总时间为890min)。3、基于饱和-非饱和流理论及溶质运移理论,采用GMS中的FEMWATER模块构建饱和非饱和带中由对流、弥散、吸附等影响因素共同作用下的硝基苯迁移转化耦合模型。4、模型结果(1)模拟河流不同污染程度对地下水的影响,随着河流污染源的浓度的增大,地下水受污染的程度相应地增大。(2)模拟不同河流与地下水转化关系下的饱和非饱和带中硝基苯的溶质运移规律,当河流与地下水处于临界“脱节”时,溶质运移速度最快。更多还原

【Abstract】 The study of river pollution to groundwater during pumping near a stream has great theoretical and practical significance to development and innovation solute transport theory and research method in aquifer under rivers.Based on the relationship between river and groundwater, the paper studied on water flow and solute transport rule about conservative substance NaCl and non-conservative substance nitrobenzene in river-impendent zone of saturation-zone of aeration-zone of saturation system, combined with indoor physical simulation experiment and numerical simulation. Considering the factor of convection, dispersion and adsorption, a water flow and solute transport coupling model has been built to quantificationally describe the influence of river pollution to groundwater.The following conclusions can be concluded:1、under the condition of no water driving effect, with the increase of time, the solute transport rule shows the gravity differentiation phenomenon. This conclution show that without water driving effect, gravity is an important factor in the process of solute transport.2、Solute transport disciplines in river and groundwater show:the farther from the river, the longer concentration changing time is in horizontal direction; the distribution of solute concentration in the groundwater is changed from the inhomogeneous state in the upper section to the homogeneous state in lower section with the experiment time duration and the increasement of solute transport distance. The speed of solute transport becomes fast with the increase of pumping intensity in saturation zone. As the river and groundwater has unified water level (Plan A-160-130, total time of experiment is 2265min); as the water level is critical disjoined (Plan C-160-90, total time of experiment is 765min); after the water level disconnection (Plan F-160-40, total time of experiment is 890min), solute transport is slightly lower.3、Based on the theory of saturated-unsaturated flow and solute transport, water flow and solute transport about nitrobenzene in the system of river and groundwater is modeled mathematically using FEMWATER module in the GMS.4、Modelling results(1) Once the relationship of river and groundwater stays the same, with the increase of solute concentration, the pollution degree in groundwater increases. (2) The migration of nitrobenzene in groundwater is varying with changing relationship of river and groundwater. When the river level is changeless, the discharge level is critical "disjunction", the speed of solute transport is fastest.更多还原