Sismic refraction exploration for groundwater potential evaluations: A case study of Vientiane province, Laos

Recently, there has been increased interest in the use of seismic refraction surveys for the exploration of groundwater investigations. The aim of this study is to delineate groundwater potential zones using the seismic refraction technique. SmartSeis ST, with 12 channels seismograph was selected for seismic refraction data acquisition in Phonhong district of Vientiane Province, Laos.
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Sismic refraction exploration for groundwater potential evaluations: A case study of Vientiane province, Laos VNU Journal of Science: Earth and Environmental Sciences, Vol. 36, No. 4 (2020) 90-101 Original Article Seismic Refraction Exploration for Groundwater Potential Evaluations: A Case Study of Vientiane Province, Laos Viengthong Xayavong1,3,, Vu Duc Minh1, Nguyen Anh Duong2, Vu Minh Tuan2 1 VNU University of Science, 334 Nguyen Trai, Hanoi, Vietnam. 2 Institute of Geophysics, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam. 3 Faculty of Natural Science, National University of Laos, Dongdok Campus 7322, Vientiane, Laos. Received 25 June 2020 Revised 24 August 2020; Accepted 31 August 2020 Abstract: Recently, there has been increased interest in the use of seismic refraction surveys for the exploration of groundwater investigations. The aim of this study is to delineate groundwater potential zones using the seismic refraction technique. SmartSeis ST, with 12 channels seismograph was selected for seismic refraction data acquisition in Phonhong district of Vientiane Province, Laos. The seismic velocities distribution analysis indicated that there are three different subsurface lithological zones ranging between (300–750m/s), (700–1650m/s), and (1500–2100m/s). Gradual increase of seismic velocity indicates changes of lithological layers with vertical depth. This velocity increase is due to the dense lithological formation which changes vertically deep from alluvial sediments to dry sand and then to siltstone and gravel layers according to the borehole data. The seismic refraction results show that the aquifer is a sand and gravel aquifer with a thickness of unclear. The depth to the groundwater saturated layers ranging from 10 m to 25 m. The results of this study have indicated that the application of the seismic refraction exploration method to find groundwater is feasible and effective and can delineate groundwater potential zones in Laos. Keywords: Groundwater, aquifers, seismic refraction exploration, Vientiane, Laos.________ Corresponding author. E-mail address: viengthongxv@gmail.com https://doi.org/10.25073/2588-1094/vnuees.4651 90 V.T. Xayavong et al. / VNU Journal of Science: Earth and Environmental Sciences, Vol. 36, No. 4 (2020) 90-101 911. Introduction domestic supply in rural areas [3]. Unfortunately, 60% of the 118 deep wells drilled Groundwater is an essential source as were could not be used due to poor water quality,freshwater in around the world, whereas a such as high salinity [4]. As drilling is expensive,growing number of countries in Southeast Asia it will be of great benefit if advanced geophysicalhave encountered serious groundwater quantity methods, especially seismic refractionand quality problems such as declining exploration applied as reliable tools forgroundwater tables, subsidence, groundwater groundwater investigation and management [5].quality, and overexploitation leading to Nils et al. (2011a) conducted research onunsustainable management of groundwater characterization of aquifers in the Vientianeresources. These are major problems currently Basin, Laos, using Magnetic Resonancechallenging hydrogeologists and relevant Sounding and Vertical Electrical Sounding [20].organizations. Properly managed, groundwater Both MRS and VES were carried out at threeis a renewable resource, with volume varying areas namely Xaythani (Thangon), Thoulakhomwith the seasons and character of the local and Phonhong districts of Vientiane Basin.geology. Available volumes of surface water The porous aquifers are described indirectlymay vary very strongly over time, and surface through the relationship between the lithologicalwater may be susceptible to various forms of features and the body wave velocity. Severalpollution. Groundwater is an important source ...