Zha Yuanyuan, Yeh Tian-Chyi J, Illman Walter A, Tanaka Tatsuya, Bruines Patrick, Onoe Hironori, Saegusa Hiromitsu, Mao Deqiang, Takeuchi Shinji, Wen Jet-Chau
State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China.
Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ, USA.
Ground Water. 2016 Nov;54(6):793-804. doi: 10.1111/gwat.12421. Epub 2016 Apr 20.
While hydraulic tomography (HT) is a mature aquifer characterization technology, its applications to characterize hydrogeology of kilometer-scale fault and fracture zones are rare. This paper sequentially analyzes datasets from two new pumping tests as well as those from two previous pumping tests analyzed by Illman et al. (2009) at a fractured granite site in Mizunami, Japan. Results of this analysis show that datasets from two previous pumping tests at one side of a fault zone as used in the previous study led to inaccurate mapping of fracture and fault zones. Inclusion of the datasets from the two new pumping tests (one of which was conducted on the other side of the fault) yields locations of the fault zone consistent with those based on geological mapping. The new datasets also produce a detailed image of the irregular fault zone, which is not available from geological investigation alone and the previous study. As a result, we conclude that if prior knowledge about geological structures at a field site is considered during the design of HT surveys, valuable non-redundant datasets about the fracture and fault zones can be collected. Only with these non-redundant data sets, can HT then be a viable and robust tool for delineating fracture and fault distributions over kilometer scales, even when only a limited number of boreholes are available. In essence, this paper proves that HT is a new tool for geologists, geophysicists, and engineers for mapping large-scale fracture and fault zone distributions.
虽然水力层析成像（HT）是一种成熟的含水层表征技术，但将其应用于表征千米级断层和断裂带的水文地质情况却很少见。本文依次分析了来自两次新抽水试验的数据集，以及Illman等人（2009年）在日本瑞浪一个裂隙花岗岩场地分析的两次先前抽水试验的数据集。分析结果表明，先前研究中使用的断层带一侧两次先前抽水试验的数据集导致了对断裂带和断层带的不准确测绘。纳入两次新抽水试验（其中一次在断层另一侧进行）的数据集后，得出的断层带位置与基于地质测绘的位置一致。新数据集还生成了不规则断层带的详细图像，这是单独的地质调查和先前研究无法获得的。因此，我们得出结论，如果在HT调查设计过程中考虑现场地质结构的先验知识，就可以收集到关于断裂带和断层带的有价值的非冗余数据集。只有利用这些非冗余数据集，HT才能成为描绘千米尺度上断裂和断层分布的可行且强大的工具，即使只有有限数量的钻孔可用。从本质上讲，本文证明了HT是地质学家、地球物理学家和工程师绘制大规模断裂和断层带分布的新工具。
