数值模型在地下水管理中的应用

Application of numerical models in groundwater management

为进一步推动模拟工作,并使模拟尽可能标准化和规范化,介绍国际上认可的建立模型的步骤、方法以及常用的模拟软件。引用作者在国外所做的两个实例,对建立模型的步骤、方法以及模型标定方法和标定结果作了具体的介绍。国内应鼓励使用已有的国际标准化模拟软件,进一步提高建模的专门知识和技巧。数值模型是真实世界的一个数学表达,对模型的产出应有一个现实的看法和专业的理解。模型建立前,应对现场数据作详细的专业分析,以确保概念模型的正确。在模型的建设中,应把注意力放在如何使模型在水文地质和物理过程方面去逼近真实世界。模型中采用的计算条件或方法都应有水文地质依据作支持,而不能仅仅为了逼近实测数据而随意地加入无依据的计算条件,这样的模型是不可靠的,其结果将是无实际意义的或是误导的。

Overexploitation of groundwater has caused severe environmental problems in China, such as land subsidence, disappearance of surface water bodies, and groundwater pollution. In order to manage groundwater scientifically and exploit it rationally, numerical models, as powerful scientific tools, have been employed widely. Numerical modeling was a special expertise, and requires special skills. Modeling guidelines and standards should be followed in the entire process of modeling of site conceptualization, model construction, calibration, verification, application, and reporting. In China, various models were developed in modeling groundwater flow, however, most work were lack of the introduction of international standards, and were not published formally. In order to help standardize modeling work in China, international standards of modeling were introduced, as well as commonly used modeling software. Procedure of model construction, calibration and prediction using MODFLOW was further exemplified in two field cases, taken from author's work in Australia. These examples demonstrated how models were employed to predict impacts of sand mining on groundwater, and to interpret groundwatersurface water interaction in a coalmining river basin. Calibration results were also presented for both cases. These examples were expected to have reference and guidance value for further development of groundwater modeling in China. Modelers in China are encouraged to understand and adopt international modeling guidelines and standards, and to improve skills in areas of hydrogeological conceptualization, automated model calibration, and calibration measurement methods. Modelers should understand that models are mathematical representations of real systems, and should have practical and professional interpretation of modeling results. To improve models' performance, emphases should be put on hydrogeological data interpretation and site conceptualization. All computing conditions and mathematical methods used in models should be supported by hydrogeological data. Arbitrary conditions should not be added in models as this may generate misleading results.