Hydraulic Tomography in Highly Heterogeneous Geologic Media: Field and Computational Investigations

有关地下水力参数的信息对于深入了解流体流动和污染物输运过程至关重要。这些过程的详细了解是必要的地下水供应，地下水修复，提取化石燃料，核废料处置场的评价，并在原地浸出的金属等，然而，地下是异质的，在多个尺度，这显着复杂化我们对这些过程的理解。 水力层析成像（HT）作为一种新的成像方法迅速崛起的地下非均匀性的水力传导率（K）和比存储（Ss）。HT不同于地球物理层析成像，因为前者依赖于泵送或注入水作为激发源，而后者依赖于电磁信号作为源。虽然HT已被证明是一种很有前途的地下非均匀性成像方法，但迫切需要检查：1）其他现场数据是否可以改善HT结果; 2）HT在更大尺度上是否有效; 3）HT在破碎岩石地形中是否有效。因此，我们将首先检查融合其他站点数据的有效性（例如，地质、地球物理和地球化学）与抽水试验数据对HT结果的影响。接下来，该项目将研究在比以前尝试的大得多的规模（100到1000米）进行HT调查的可行性。最后，本项目还将研究HT对破碎岩石的适用性。总的来说，这些研究项目将有助于确定HT是否可以显着改善各种行业（水，修复，能源，采矿等）所需的分辨率和规模相关的地下表征工作。 拟议的研究重点是进行补充领域和计算调查，应显着提高我们的能力，以映射在多孔和裂缝地质介质的地下异质性。这种能力的发展也将使我们能够显着推进我们的流体流动和污染物的传输过程中的高度非均质地质介质的基本理解。

Information about subsurface hydraulic parameters is critical for thorough understanding of fluid flow and contaminant transport processes. A detailed understanding of these processes is necessary for the evaluation of groundwater supplies, groundwater remediation, extraction of fossil fuels, evaluation of nuclear waste disposal sites, and in situ leaching of metals, etc. However, the subsurface is heterogeneous at multiple scales and this significantly complicates our understanding of these processes. Hydraulic tomography (HT) is rapidly emerging as a new method to image the subsurface heterogeneity of both hydraulic conductivity (K) and specific storage (Ss). HT is different from geophysical tomography, as the former relies on pumping or injection of water as a source of excitation, while the latter relies on electromagnetic signals as sources. While HT has been shown to be a promising method for imaging subsurface heterogeneity, there is a critical need to examine whether: 1) other site data can improve HT results; 2) HT can be effective at larger scales; and 3) HT is effective in fractured rock terrains. Therefore, we will first examine the effectiveness of fusing other site data (e.g., geological, geophysical and geochemical) with pumping test data on HT results. Next, this project will examine the feasibility of conducting HT surveys at a considerably larger scale (100's to 1000's m) than previously attempted. Lastly, this project will also examine the applicability of HT to fractured rocks. Collectively, these research projects will help determine whether HT can significantly improve subsurface characterization efforts relevant at the resolution and scale necessary for various industries (water, remediation, energy, mining, etc.). The proposed research focuses on conducting complementary field and computational investigations that should significantly advance our capabilities to map subsurface heterogeneity in porous and fractured geologic media. Development of such capabilities will also allow us to significantly advance our fundamental understanding of fluid flow and contaminant transport processes in highly heterogeneous geologic media.