B. Zawilski, F. Granouillac, N. Claverie, Baptiste Lemaire, A. Brut, T. Tallec
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引用次数: 1
Abstract
Abstract. Soil water content (SWC) sensors are widely used for
scientific studies or for the management of agricultural practices. The most
common sensing techniques provide an estimate of volumetric soil water
content based on sensing of dielectric permittivity. These techniques
include frequency domain reflectometry (FDR), time domain reflectometry
(TDR), capacitance and even remote-sensing techniques such as
ground-penetrating radar (GPR) and microwave-based techniques. Here, we will
focus on frequency domain reflectometry (FDR) sensors and more specifically
on the questioning of their factory calibration, which does not take into
account soil-specific features and therefore possibly leads to inconsistent
SWC estimates. We conducted the present study in the southwest of France
on two plots that are part of the ICOS ERIC network (Integrated Carbon
Observation System, European Research and Infrastructure Consortium), FR-Lam
and FR-Aur. We propose a simple protocol for soil-specific calibration,
particularly suitable for clayey soil, to improve the accuracy of SWC
determination when using commercial FDR sensors. We compared the sensing
accuracy after soil-specific calibration versus factory calibration. Our
results stress the necessity of performing a thorough soil-specific
calibration for very clayey soils. Hence, locally, we found that factory
calibration results in a strong overestimation of the actual soil water
content. Indeed, we report relative errors as large as +115 % with a
factory-calibrated sensor based on the real part of dielectric permittivity
and up to + 245 % with a factory-calibrated sensor based on the modulus
of dielectric permittivity.
期刊介绍:
Geoscientific Instrumentation, Methods and Data Systems (GI) is an open-access interdisciplinary electronic journal for swift publication of original articles and short communications in the area of geoscientific instruments. It covers three main areas: (i) atmospheric and geospace sciences, (ii) earth science, and (iii) ocean science. A unique feature of the journal is the emphasis on synergy between science and technology that facilitates advances in GI. These advances include but are not limited to the following:
concepts, design, and description of instrumentation and data systems;
retrieval techniques of scientific products from measurements;
calibration and data quality assessment;
uncertainty in measurements;
newly developed and planned research platforms and community instrumentation capabilities;
major national and international field campaigns and observational research programs;
new observational strategies to address societal needs in areas such as monitoring climate change and preventing natural disasters;
networking of instruments for enhancing high temporal and spatial resolution of observations.
GI has an innovative two-stage publication process involving the scientific discussion forum Geoscientific Instrumentation, Methods and Data Systems Discussions (GID), which has been designed to do the following:
foster scientific discussion;
maximize the effectiveness and transparency of scientific quality assurance;
enable rapid publication;
make scientific publications freely accessible.