Geophysical investigations of the vadose zone in the Valley of Hermosillo aquifer, Sonora, Mexico

Seven Schlumberger soundings and three azimuthal soundings were conductedin the Valley of Hermosillo, Sonora, northwestern Mexico, in order to investigatethe vadose zone above the Valley of Hermosillo aquifer. This coastal aquifersystem, which is considered unconfined in its upper part, consists of...

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Bibliographic Details
Authors: Isabel Simón, J. Andrés Chavarría, Birgit Steinich, Luis E. Marín
Format: article
Status:Published version
Publication Date:1997
Country:México
Institution:Universidad Nacional Autónoma de México
Repository:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:56836304
Online Access:https://www.redalyc.org/articulo.oa?id=56836304
Access Level:Open access
Keyword:Ciencias de la Tierra
vadose zone
Valley of Hermosillo
resistivity measurements
salinisation of the soil
Description
Summary:Seven Schlumberger soundings and three azimuthal soundings were conductedin the Valley of Hermosillo, Sonora, northwestern Mexico, in order to investigatethe vadose zone above the Valley of Hermosillo aquifer. This coastal aquifersystem, which is considered unconfined in its upper part, consists of alluvialmaterial. The resistivity soundings show that lateral changes of the resistivity canbe interpreted with respect to a íbackgroundí value of 100 Wm. Resistivity valuesless than 50 Wm were found near the coast and near the population centersHermosillo and Miguel Alemán. These relatively low values may reveal the presence of low quality pore water due to irrigation with ground water mixed withbrackish ground water from sea water intrusions and with untreated sewage, or asa result of pollution by domestic and/or industrial sewage. The porosity of theselow resistivity areas was estimated to be on the order of 25 %, based on Archieíslaw. Azimuthal resistivity surveys show that there is only superficial resistivityanisotropy which may be related to a rearrangement of grains by infiltratedirrigation water.