判定地下水水动力弥散系数的综合分析法  

The Comprehensive Analysis Method for Determining Groundwater Hydrodynamic Dispersion Coefficients

作　　者：杜川[1,2] 陈素云 牛耕[1,2] 

机构地区：[1]北京市勘察设计研究院有限公司,北京100038 [2]北京市环境岩土工程技术研究中心,北京100038

出　　处：《中国农村水利水电》2017年第12期90-94,共5页China Rural Water and Hydropower

摘　　要：地下水水动力弥散系数是进行地下水污染评价及污染物运移模拟、预测过程中的一项关键参数,不同的试验类型及求解方法对应的求参结果往往会有较大差异。在结合试验区含水层条件下,提出了持续注入法与瞬时投源法两种试验思路,考虑到含水层渗透系数、给水度等参数的获取相对容易且可靠,因此,在利用上述参数建立试验区水流模型的基础上对两种不同试验类型进行溶质运移模拟,最后结合解析法与数值法两种方法互验后综合确定试验区弥散系数。其中,在使用解析法对瞬时投源试验参数计算中提出全程最优曲线拟合法,从试验整体数据出发,在误差平方和最小原则下进行参数优化。结果表明,在数值模拟所需的基础参数准确的前提下,数值法能较准确、直观的体现计算值与实测值浓度变化情况,进而通过调整参数得到准确结果。不同水力特征下的试验类型所反映的参数结果更加客观真实。此类基于不同试验类型与求参方法相结合的综合分析思路为今后不同地质条件下弥散系数的确定起到了较好的指导意义。Groundwater hydrodynamic dispersion coefficient is a key parameter for the evaluation of groundwater pollution and simulation and forecast of pollutant migration, the parameters corresponding to different test types and solutions. In this paper, two test ideas of continuous injection method and instantaneous source method are put forward in combination with aquifer conditions in experiment zones. Considering that the parameters such as permeability coefficient, specific yield are easily and reliably confirmed, based on the above parameters, the flow model of the experiment zone is established and then solute transport is modeled. Finally, analytical method and numerical method are combined to determine the dispersion coefficient. In the process of using analytical method for instantaneous source method, optimal curve fitting all the way is put forward and parameter optimization is carried out under the principle of minimum error variance. The results show that, considering the required parameters are accurate in numerical simulation, numerical method can accurately and intuitively reflect the concentration change of the calculation and measurement values, and then get accurate results by adjusting parameters. The parameters＂ results reflected by the two types of tests under different hydraulic characteristics are more objective and accurate. Such ideas about combining different test types and extracting parameter methods plays a good guiding role in determining the dispersion coefficient under different geological conditions in the future.

关 键 词：弥散系数 持续注入试验 瞬时投源试验 解析法 数值法 全程曲线拟合法 

分 类 号：TV138[水利工程—水力学及河流动力学]