Geological models are used for a range of applications relevant for engineering geology and the demands for reliable geological models with realistic uncertainty assessments are therefore increasing. The geological modelling workflow is divided into multiple steps, each associated with uncertainties. Often however, many of these sources of uncertainty are overlooked, which may lead to an underestimation of the uncertainties of the final model. The main reason is that most of the steps in the geological modelling workflow are subjective to some degree. Thus, the possible sources of uncertainty in geological modelling are theoretically infinite, and without a trustworthy conceptual model to outline the expected geological structures and lithologies, the uncertainty assessment of the resulting model will likewise be unreliable. In this paper, we describe the chain of uncertainties in the geological modelling workflow and showcase some of the most important sources of uncertainties through practical modelling examples from two different model areas. The paper also presents and discuss a method to conduct qualitative uncertainty assessment, which is conducted by the modeler and based on expert evaluation and prioritization of the different sources of uncertainty. The practical use of the uncertainty assessment method is exemplified in the last two examples, representing a local-scale and a large-scale model, respectively. All four examples are from Danish geological models that have been constructed as interpretation-based layer-models. However, the considerations regarding the uncertainties in the chain of the geological modelling workflow are useful regardless of the modelling method.

中文翻译：

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评估 3D 地质建模工作流程中的不确定性链


地质模型用于与工程地质学相关的一系列应用，因此对具有真实不确定性评估的可靠地质模型的需求正在增加。地质建模工作流程分为多个步骤，每个步骤都与不确定性相关。然而，许多这些不确定性来源往往被忽视，这可能导致对最终模型的不确定性的低估。主要原因是地质建模工作流程中的大多数步骤在某种程度上都是主观的。因此，地质建模中可能的不确定性来源在理论上是无限的，如果没有一个值得信赖的概念模型来概述预期的地质结构和岩性，对结果模型的不确定性评估同样是不可靠的。在本文中，我们描述了地质建模工作流程中的不确定性链，并通过来自两个不同模型领域的实际建模示例展示了一些最重要的不确定性来源。本文还提出并讨论了一种进行定性不确定性评估的方法，该方法由建模者进行，并基于专家评估和对不同不确定性来源的优先级。不确定性评估方法的实际应用在最后两个例子中举例，分别代表局部尺度和大规模模型。所有四个示例均来自丹麦地质模型，这些模型已被构建为基于解释的图层模型。然而，无论采用何种建模方法，对地质建模工作流程链中不确定性的考虑都是有用的。