High-resolution profiling of alluvial aquifer in potential riverbank filtration site by use of combining CMP refraction and reflection seismic methods

Hydrogeological conditions, such as aquifer thicknesses, sediments and structure of alluvium, are important factors in determining the available intake of water by riverbank filtration (RBF). To understand the hydrogeology of a potential RBF site in Korea, high-resolution seismic surveys were conducted using refraction and reflection methods. The depth of the groundwater table in the study area was clearly shown in common mid-point (CMP) refraction seismic sections and ranged in depth from 2 to 9m below ground surface. The lower boundary of the alluvial aquifer overlies bed rock and was easily delineated in the reflection sections using the P-beam method. The lower boundary of the alluvium ranges in depth from about 30 to 46m below ground surface. The CMP refraction and P-beam methods have many advantages in the field work and during data analysis because these methods can be applied to data obtained by conventional land seismic reflection surveys. The high-resolution seismic survey, combined with CMP refraction and P-beam methods, is a powerful tool to obtain subsurface information and evaluate potential RBF sites.