Six conceptually different transport models were applied to the macrodispersion experiment (MADE)-1 field tracer experiment as a first major attempt for model comparison. The objective was to show that complex mass distributions in heterogeneous aquifers can be predicted without calibration of transport parameters, solely making use of structural and flow data. The models differ in their conceptualization of the heterogeneous aquifer structure, computational complexity, and use of conductivity data obtained from various observation methods (direct push injection logging, DPIL, grain size analysis, pumping tests and flowmeter). They share the same underlying physical transport process of advection by the velocity field solely. Predictive capability is assessed by comparing results to observed longitudinal mass distributions of the MADE-1 experiment. The decreasing mass recovery of the observed plume is attributed to sampling and no physical process like mass transfer is invoked by the models. Measures like peak location and strength are used in comparing the modeled and measured plume mass distribution. Comparison of models reveals that the predictions of the solute plume agree reasonably well with observations, if the models are underlain by a few parameters of close values: mean velocity, a parameter reflecting log-conductivity variability, and a horizontal length scale related to conductivity spatial correlation. The robustness of the results implies that conservative transport models with appropriate conductivity upscaling strategies of various observation data provide reasonable predictions of plumes longitudinal mass distribution, as long as key features are taken into account.

中文翻译：

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使用不同类型的水力数据实施的 MADE-1 实验的六种传输模型的比较


六种概念上不同的输运模型被应用于宏观色散实验（MADE）-1 场示踪剂实验，作为模型比较的第一次主要尝试。目的是表明，无需校准传输参数，仅利用结构和流量数据即可预测异质含水层中的复杂质量分布。这些模型的不同之处在于非均质含水层结构的概念化、计算复杂性以及从各种观测方法（直推注入测井、DPIL、粒度分析、泵送测试和流量计）获得的电导率数据的使用。它们共享相同的仅通过速度场进行的平流物理传输过程。通过将结果与 MADE-1 实验观察到的纵向质量分布进行比较来评估预测能力。观察到的羽流质量恢复的减少归因于采样，并且模型没有调用诸如质量传递之类的物理过程。峰值位置和强度等测量用于比较建模和测量的羽流质量分布。模型比较表明，如果模型以几个接近值的参数为基础，则溶质羽流的预测与观测结果相当吻合：平均速度、反映对数电导率变化的参数以及与电导率空间相关的水平长度尺度相关性。结果的稳健性意味着，只要考虑到关键特征，采用各种观测数据的适当电导率放大策略的保守输运模型就可以提供羽流纵向质量分布的合理预测。