Page 72 - Demo

A Subsoil Inspection in a Mangrove Habitat Using Electrical Resistivity Tomography60Marine Research of the National Academy of Marine ResearchDOI: 10.29677/MR.202406_4(1).00053 ELECTRICAL RESISTIVITY TOMOGRAPHYINSPECTION The electrical resistivity tomography (ERT) method is a non-destructive approach used for subsurfaceinvestigation. Conrad Schlumberger first performed electrical resistivity field surveys in the beginning of the 20th century (Ward, 1980). Since then, this method has been evolving and advancing, branching out into new application fields. During the past few decades, its development has been particularly rapid, considering the introduction of innovative efficient instruments and the fast progress of easily available computational power (Sj%u00f6dahl, 2006). The ERT method has been used for a wide range of near-surface geological, engineering, and environmental purposes (Ward, 1990; Wightman et al., 2003; Daily et al., 2005; Sj%u00f6dahl, 2006; Society ofExploration Geophysicists of Japan, 2014). The ERT technique can identify or localize geological layers, faults, groundwater pollutants, cavities, mining strata, burial layers, and landslide mass; in addition, it has been used for various practical applications. For example, this survey method can explore construction materials, such as sand and gravel within the mining industry, support site investigations and geotechnical applications for all types of civil engineering projects, and map soil/bedrock interfaces, groundwater levels, faults, and cross zones in geological prospecting fields. The applications of the ERT inspection technique cover several areas, such as monitoring of potential landslides, contamination and integrity in landfills, leakage or seepage monitoring in embankment dams or barriers, salt-water intrusion in coastal areas, pollution investigations or control in mining sites, exploration and protection of groundwater resources, geothermal investigation in energy industry, or archaeological delineation (e.g., Ward, 1990; Dahlin, 1993; Pellerin, 2002). Overall application fields are listed belo3.1 Background and applicationGeological exploration field: The ERT technology can be used for (a) on-site interpretating or positioning of strata, fault zones, groundwater pollutants, cavities, mineral layers, and buried layers; (b)identifying the interfaces between soil weathering zones and bedrocks; (c) on-site positioning surveys of fault zones, shear zones, fracture zones, colluvium, or sliding surfaces; and (d) large-scale surveys for groundwater veins or aquifers (Liao et al., 2019).(1)Engineering application field: (a) exploring construction materials, mining sand, and gravel; (b) assisting in-situ investigations and geotechnical applications of various civil engineering projects, such as watertightness investigation for rockfill dam site selection (Hung, 2022), groundwater recharge affected by seasonal factors in reservoir watersheds (Tesfaldet and Puttiwongrak, 2019); (c) monitoring post-disaster slope failures (Schuster and Krizek, 1978; Wightman et al., 2003; Lin et al., 2019; TGS, 2011); and (d) additionally remarking borehole sampling data by using in-hole ERT surveys (Lin et al., 2019).(2)Environmental remediation and other fields: Underground pollutants and integrity of landfills, leakage and seepage of embankments or weirs, seawater intrusion in coastal areas, pollution investigation or control in mining areas, exploration and protection of groundwater resources, geothermal surveys of energy industry, and archaeological zoning (Ward, 1990; Dahlin, 1993).(3)