Delimiting a saline water zone in Quaternary fluvial–alluvial deposits using transient electromagnetic: a case study in Punata, Bolivia

Research output: Contribution to journalArticle

Abstract

The semiarid Punata alluvial fan is located in the central part of Bolivia. The main activity of this region is the extensive agriculture, and groundwater is the main water supply. Local villagers who use groundwater reported that in some places groundwater has a salty taste. In order to investigate the origin of this problem, several TEM soundings were performed in the study area, and they were complemented with ERT surveys. The results show top layers with resistivity values ranging from 30 to 200 Ωm and a bottom layer with resistivity values ranging from 1 to 20 Ωm, which might be interpreted as the main aquifer and a layer with high clay content, respectively. Between the top and bottom layer, a transition zone with saline water has been identified, with resistivity values ranging from 0.1 to 1 Ωm. The origin of this closed-basin brine might be a product of the evaporation of paleolakes during the lower Pliocene, where saline clays were deposited. This study demonstrated the effectiveness of TEM sounding for mapping very low resistivity zones such as saline water.

Details

Authors
Organisations
External organisations
  • Universidad Mayor de San Simon
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Geophysics

Keywords

  • Geophysics, Groundwater characterization, Saline water, Transient electromagnetic
Original languageEnglish
Article number46
JournalEnvironmental Earth Sciences
Volume77
Issue number2
Publication statusPublished - 2018 Jan 1
Publication categoryResearch
Peer-reviewedYes