Quantification of Uncertainties from Image Processing and Analysis in Laboratory-Scale DNAPL Release Studies Evaluated by Reflective Optical Imaging
Quantification of Uncertainties from Image Processing and Analysis in Laboratory-Scale DNAPL Release Studies Evaluated by Reflective Optical Imaging
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DOI：
10.3390/w11112274
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发表时间：
2019-10
期刊：
影响因子：
3.4
通讯作者：
Christian Engelmann;Luísa Schmidt;C. Werth;M. Walther
中科院分区：
文献类型：
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作者：
Christian Engelmann;Luísa Schmidt;C. Werth;M. Walther
来自（非）故意泄漏的地下DNAPL（致密非水相液体）污染通常导致严重的环境危害。大量的研究已经证明了DNAPL源区几何形状的相关性，用于确定污染物羽流在地下水中的传播。光学成像是一种很有前途的非侵入性方法，用于识别DNAPL饱和度，而不干扰多相流动力学。然而，工作流程和图像分析方法还没有被充分开发或描述用于相关实验工作的一般应用。例如，用于相位着色的染料的选择影响图像处理，并且可能使DNAPL饱和度的最终估计有偏差。在这项研究中，我们进行了一系列的DNAPL迁移和截留的研究，在透明的坦克，充满了三种不同类型的多孔介质。使用不同的染料并获取原始图像。随后，这些用于评估一套图像处理和分析方法，这些方法被组织成一个工作流程。我们的方法使我们能够识别引入最多错误的关键图像处理和分析步骤。适用的染料配置导致高达41%的不确定性取决于选择的处理步骤。基于这些研究结果，它是可能的描绘一个灵活的框架，图像处理和分析，有可能在其他坦克实验装置的转移和应用。
Subsurface DNAPL (dense non-aqueous phase liquid) contamination from (un-) intentional spilling typically leads to severe environmental hazards. A large number of studies have demonstrated the relevance of DNAPL source zone geometry for the determination of contaminant plume propagation in groundwater. Optical imaging represents a promising non-invasive method for identifying DNAPL saturation without disturbing multiphase flow dynamics. However, workflow and image analysis methodologies have not been sufficiently developed or described for general application to related experimental efforts. For example, the choice of dye(s) used for phase colorization affects image processing and can bias final estimations of DNAPL saturations. In this study, we perform a series of DNAPL migration and entrapment studies in transparent tanks that are filled with three different types of porous media. Different dyes are used and raw images are acquired. Subsequently, these are used to evaluate a suite of image processing and analysis approaches, which are organized into a workflow. Our approach allows for us to identify key image processing and analysis steps that introduce the most error. Applicable dye configurations led to uncertainties of up to 41% depending on the selection of processing steps. Based on these findings, it was possible to delineate a flexible framework for image processing and analysis that has the potential for transfer and application in other tank experiment setups.