Fast Mapping of Soil Moisture Using Calibrated Frequency-Domain Electromagnetic Methods in Wet and Dry Soils of Central Chile

46 Pages Posted: 1 Aug 2023

See all articles by gonzalo yanez

gonzalo yanez

affiliation not provided to SSRN

Jaime Araya Vargas

affiliation not provided to SSRN

Catalina Lizarde

affiliation not provided to SSRN

Pilar M. Gil

affiliation not provided to SSRN

Víctor García

affiliation not provided to SSRN

Fernanda Gallegos

affiliation not provided to SSRN

Francisco Meza

Pontificia Universidad Católica de Chile

José Schmidt

affiliation not provided to SSRN

Jorge Sanhueza

affiliation not provided to SSRN

Abstract

Soil moisture at shallow depths (<2 m) is a key parameter for a variety of processes associated with the growth and development of natural and intervened ecosystems, including water needs for irrigation in farms, soil available water for ecosystem growth in sclerophyll forest, wetland characterization, and climate change assessment, among others. Traditional techniques provide reliable but invasive and not necessarily representative soil moisture values for large fields (e.g., capacitance probes, gravimetric methods). Non-invasive geophysical electromagnetic techniques, in particular Frequency Domain Electromagnetic Techniques (FDEM) are able to address the aforementioned limitations. However, frequency domain techniques require a proper calibration to obtain a confident resistivity value. We present a novel, reliable, and quick technique to calibrate a single-frequency FDEM equipment. This technique includes, as a first step, to conduct punctual vertical electrical sounding (VES) measurements to estimate a simple layered electrical resistivity model, in order to estimate the corrected zero-offset FDEM response. We assessed the performance of this approach against electrical resistivity tomography (ERT) measurements in seven sites located in Central Chile, encompassing a wide spectrum of soil moisture conditions. Our analysis indicates that non-corrected FDEM data can produce apparent electrical resistivity values that are biased in excess of 100% compared to ERT data. By contrast, electrical resistivity models derived from corrected FDEM data are comparable to ERT inversion results in the range of 0.3-0.8m soil depth. Furthermore, soil moisture estimates derived from corrected FDEM models show significant departures from uncorrected data. Our findings suggest that the propose methodology represent an adequate tool for a massive and fast estimate of soil moisture under different vegetation and soil types.

Keywords: Geophysics, Frequency Domain Electromagnetic, Electrical resistivity tomography, Geoelectrical Soil Characterization, Soil water content

Suggested Citation

yanez, gonzalo and Vargas, Jaime Araya and Lizarde, Catalina and Gil, Pilar M. and García, Víctor and Gallegos, Fernanda and Meza, Francisco and Schmidt, José and Sanhueza, Jorge, Fast Mapping of Soil Moisture Using Calibrated Frequency-Domain Electromagnetic Methods in Wet and Dry Soils of Central Chile. Available at SSRN: https://ssrn.com/abstract=4528523 or http://dx.doi.org/10.2139/ssrn.4528523

Gonzalo Yanez (Contact Author)

affiliation not provided to SSRN ( email )

No Address Available

Jaime Araya Vargas

affiliation not provided to SSRN ( email )

No Address Available

Catalina Lizarde

affiliation not provided to SSRN ( email )

No Address Available

Pilar M. Gil

affiliation not provided to SSRN ( email )

No Address Available

Víctor García

affiliation not provided to SSRN ( email )

No Address Available

Fernanda Gallegos

affiliation not provided to SSRN ( email )

No Address Available

Francisco Meza

Pontificia Universidad Católica de Chile ( email )

Av Libertador General Bernardo O'Higgins 340
Santiago, Región Metropolitana 8331150
Chile

José Schmidt

affiliation not provided to SSRN ( email )

No Address Available

Jorge Sanhueza

affiliation not provided to SSRN ( email )

No Address Available

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Downloads
25
Abstract Views
96
PlumX Metrics