Visualization of downwelling, upwelling and flow of water through sediments using resistivity, IP and SP techniques

Abstract

Identifying and understanding the processes of downwelling, upwelling and flow of water requires several studies of the subsurface deposits. Sediments types and extension, structural conditions, pervious and impervious deposits, dry and water-bearing sediments, and water quality as well as hydraulic conductivity of sediments are interesting required characteristics for understanding these processes. Therefore, resistivity, time-domain induced polarization (IP) and spontaneous polarization (SP) methods, field geological and hydrogeological data were conducted to realize this study. Accordingly, the lithological identification, water depth and groundwater zonation were determined. A three-dimensional (3D) resistivity modeling and hydrolithological modeling of sediments were designed to determine their types, extent, water content, water quality and sources. Due to ambiguity in resistivity outputs, the IP method was applied. 3D modeling of chargeability was constructed to differentiate between the deposits and their sedimentlogical and water characteristics, such as separating clay layers from non-clay layers and saltwater. The previous two methods were then supported by building 2D and 3D SP modeling to determine the groundwater flow, specific hydraulic conductivity, infiltration, downwelling and upwelling of water. Thus, the combination of the three methods assisted in understanding, determining and visualizing the deposits properties, downwelling, upwelling and flow of water through them. Accordingly, in addition to understanding and detecting the previous processes, this methodology and its outputs can be applied in studying aquifer recharge, pollutants transport, and seawater invasion through sediments.