藁城市地下水回灌示范场地数值模拟研究

发布时间：2018-10-23 06:40

【摘要】：由于地下水的超采,华北平原的地下水资源面临严重短缺和生态环境恶化的现状,因此,如何合理规划利用水资源及增加地下水资源的储存量成为研究的重点问题。地下水人工回灌技术在补充地下水资源方面,占有很大作用。本文选取藁城市梨园庄村地下水人工回灌试验场地作为研究区,分析地下水人工补给的效果。以藁城市梨园庄村人工回灌试验场的地质、水文地质条件分析为基础,运用2013-2014年资料,采用GMS地下水模拟软件,建立了地下水数值模拟模型,通过水位过程线的拟合识别校正了水文地质参数,并基于地下水回灌试验数据对模型进行进一步验证,说明所建立的模型达到精度要求,基本反映地下水流系统的水力特征,并分析其水均衡情况,从而为回灌预测模型提供合理的参数。在水流模型的基础上建立了地下水回灌数值模型,根据回灌井数目设计了单井与多井联合回灌两种回灌方案并分析比较了这两种方案的回灌效果。结果说明,利用地下水人工回灌,没有使得研究区地下水储存资源量有效恢复,未产生较好的资源效益,这主要是因为研究区范围较小,封闭性不够好,侧向流出量较大。方案一较无回灌相比,回灌结束时,潜水含水层水位变幅在0.1m以上的影响范围为0.54km2,地下水位最大升高5.2m;方案二较无回灌相比,回灌结束时,潜水含水层水位变幅在0.1m以上的影响范围为0.38km2,地下水位最大升高1.3m。方案二与方案一比较,整体上水位上升幅度都比较小。在回灌方案一的基础上建立了场地溶质运移模型,选择TDS、总硬度和亚硝酸盐氮三种指标进行模拟计算,分析回灌水中各项指标在回灌结束后的变化分布规律。结果显示:潜水含水层中的TDS、总硬度和亚硝酸盐氮受回灌影响的范围分别为34343m2、34877 m2和27929 m2。整体上,随着溶质在地下水中的不断运移,回灌水浓度高出地下水初始浓度值的溶质或指标(亚硝酸盐氮)会在对流扩散、水动力弥散等作用下逐渐降低;回灌水浓度低于地下水初始浓度值的溶质或指标(TDS和总硬度)可有效降低临近区域的相应浓度。
[Abstract]:Due to the overexploitation of groundwater, groundwater resources in North China Plain are faced with serious shortage and deterioration of ecological environment. Therefore, how to rationally plan and utilize water resources and increase the storage and storage of groundwater resources has become a key issue in the study. Artificial recharge of groundwater plays an important role in replenishing groundwater resources. In this paper, the artificial recharge test site of groundwater in Liyuanzhuang Village of Gaocheng City was selected as the research area to analyze the effect of artificial recharge of groundwater. Based on the analysis of geological and hydrogeological conditions of artificial recharge test site in Liyuanzhuang Village in Gaocheng City, the numerical simulation model of groundwater was established by using the data of 2013-2014 and GMS software. The hydrogeological parameters are corrected by the fitting identification of the water level process line, and the model is further verified based on the groundwater recharge test data, which shows that the established model meets the precision requirements and basically reflects the hydraulic characteristics of the groundwater flow system. The water balance is analyzed so as to provide reasonable parameters for the recharge prediction model. Based on the flow model, a numerical model of groundwater recharge is established. According to the number of recharge wells, two combined recharge schemes of single well and multi-well are designed, and the effects of the two schemes are analyzed and compared. The results show that the artificial recharge of groundwater does not effectively restore the amount of groundwater resources stored in the study area, and does not produce better resource benefit, which is mainly due to the small scope of the study area, the poor sealing and the large amount of lateral outflow. At the end of the recharge, the range of water level variation above 0.1 m is 0.54 km ~ 2, and the maximum increase of groundwater level is 5.2 m, and the second scheme is less than no recharge, and at the end of the recharge, the maximum increase of groundwater level is 5.2 m. The range of variation of groundwater level above 0.1 m is 0.38 km ~ 2, and the maximum increase of groundwater level is 1.3 m. Scheme two compares with scheme one, the rise of water level is small on the whole. On the basis of the recharge scheme 1, the site solute transport model was established. The total hardness of TDS, and nitrite nitrogen were selected to simulate and calculate, and the variation and distribution of each index in the recharge water after the recharge was finished were analyzed. The results show that the total hardness of TDS, and the range of nitrite nitrogen affected by the recharge are 34343m2m2Ni34877m2 and 27929 m2 respectively. As a whole, with the continuous migration of solute in groundwater, the solute or index (nitrite nitrogen), which is higher than the initial concentration of groundwater, will gradually decrease under the action of convection diffusion and hydrodynamic dispersion. The solute or index (TDS and total hardness) of reirrigation concentration lower than the initial concentration of groundwater can effectively reduce the corresponding concentration in the adjacent area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P641.25

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