The laboratory calibration of a soil moisture capacitance probe in sandy soils
Determining and mitigating landslide risk is a technical-scientific objective, particularly for the protection and proper territorial management and planning. The slope stability depends on the pore pressure distribution, which is influenced by the saturation front propagation through the unsaturate...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Czech Academy of Agricultural Sciences
2020-06-01
|
| Series: | Soil and Water Research |
| Subjects: | |
| Online Access: | https://swr.agriculturejournals.cz/artkey/swr-202002-0002_the-laboratory-calibration-of-a-soil-moisture-capacitance-probe-in-sandy-soils.php |
| _version_ | 1797897774088323072 |
|---|---|
| author | Marina Campora Anna Palla Ilaria Gnecco Rossella Bovolenta Roberto Passalacqua |
| author_facet | Marina Campora Anna Palla Ilaria Gnecco Rossella Bovolenta Roberto Passalacqua |
| author_sort | Marina Campora |
| collection | DOAJ |
| description | Determining and mitigating landslide risk is a technical-scientific objective, particularly for the protection and proper territorial management and planning. The slope stability depends on the pore pressure distribution, which is influenced by the saturation front propagation through the unsaturated zone, whose monitoring is useful to understand any possible instabilities. Such monitoring may be undertaken by sensors based on the measurement of the relative dielectric permittivity. Reliable relationships between the measurement and the soil moisture are necessary. The main objective of this study is to assess a laboratory calibration protocol for a specific capacitance sensor (Drill & Drop, Sentek Sensor Technologies). Two monogranular sands have been selected for the calibration purpose. The laboratory tests were performed under three relative density values (DR equal to 40%, 60% and 80%) for seven volumetric water content values (θv ranging from 0.00% to 36.26%). Based on the experimental measurements, the soil-specific calibration curves were determined at an assigned relative density value; in particular, a simple power law is adopted to describe the probe's reading as a function of the volumetric water content. The results point out that the relative density values slightly affect the tests, thus, the soil-specific calibration curves are derived based on a simple regression analysis fitting the whole set of the laboratory tests validated for each sand. The calculated coefficient of determination (R2 = 0.96/0.99) and root mean square error (RMSE = 1.4%/2.8%) values confirm the goodness of fit. In order to propose more general fitting curves, suitable for both the investigated sands, multiple linear regressions are performed by considering θv and the mean grain size, D50 as independent variables; again, the R2 and RMSE values equal to 0.97 and 2.41%, respectively, confirm the suitability of the calibration curve. Finally, the laboratory calibration curves are compared with the manufacturer-supplied curves, thus, enhancing the need for the soil-specific calibration. |
| first_indexed | 2024-04-10T08:03:42Z |
| format | Article |
| id | doaj.art-0ad5d620f209485b85e1f114fb7e8e37 |
| institution | Directory Open Access Journal |
| issn | 1801-5395 1805-9384 |
| language | English |
| last_indexed | 2024-04-10T08:03:42Z |
| publishDate | 2020-06-01 |
| publisher | Czech Academy of Agricultural Sciences |
| record_format | Article |
| series | Soil and Water Research |
| spelling | doaj.art-0ad5d620f209485b85e1f114fb7e8e372023-02-23T03:48:44ZengCzech Academy of Agricultural SciencesSoil and Water Research1801-53951805-93842020-06-01152758410.17221/227/2018-SWRswr-202002-0002The laboratory calibration of a soil moisture capacitance probe in sandy soilsMarina Campora0Anna Palla1Ilaria Gnecco2Rossella Bovolenta3Roberto Passalacqua4Genoa, ItalyDepartment of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa, ItalyDepartment of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa, ItalyDepartment of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa, ItalyDepartment of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa, ItalyDetermining and mitigating landslide risk is a technical-scientific objective, particularly for the protection and proper territorial management and planning. The slope stability depends on the pore pressure distribution, which is influenced by the saturation front propagation through the unsaturated zone, whose monitoring is useful to understand any possible instabilities. Such monitoring may be undertaken by sensors based on the measurement of the relative dielectric permittivity. Reliable relationships between the measurement and the soil moisture are necessary. The main objective of this study is to assess a laboratory calibration protocol for a specific capacitance sensor (Drill & Drop, Sentek Sensor Technologies). Two monogranular sands have been selected for the calibration purpose. The laboratory tests were performed under three relative density values (DR equal to 40%, 60% and 80%) for seven volumetric water content values (θv ranging from 0.00% to 36.26%). Based on the experimental measurements, the soil-specific calibration curves were determined at an assigned relative density value; in particular, a simple power law is adopted to describe the probe's reading as a function of the volumetric water content. The results point out that the relative density values slightly affect the tests, thus, the soil-specific calibration curves are derived based on a simple regression analysis fitting the whole set of the laboratory tests validated for each sand. The calculated coefficient of determination (R2 = 0.96/0.99) and root mean square error (RMSE = 1.4%/2.8%) values confirm the goodness of fit. In order to propose more general fitting curves, suitable for both the investigated sands, multiple linear regressions are performed by considering θv and the mean grain size, D50 as independent variables; again, the R2 and RMSE values equal to 0.97 and 2.41%, respectively, confirm the suitability of the calibration curve. Finally, the laboratory calibration curves are compared with the manufacturer-supplied curves, thus, enhancing the need for the soil-specific calibration.https://swr.agriculturejournals.cz/artkey/swr-202002-0002_the-laboratory-calibration-of-a-soil-moisture-capacitance-probe-in-sandy-soils.phpparticle size distributionregression analysisrelative densitysoil water monitoringvolumetric water content |
| spellingShingle | Marina Campora Anna Palla Ilaria Gnecco Rossella Bovolenta Roberto Passalacqua The laboratory calibration of a soil moisture capacitance probe in sandy soils Soil and Water Research particle size distribution regression analysis relative density soil water monitoring volumetric water content |
| title | The laboratory calibration of a soil moisture capacitance probe in sandy soils |
| title_full | The laboratory calibration of a soil moisture capacitance probe in sandy soils |
| title_fullStr | The laboratory calibration of a soil moisture capacitance probe in sandy soils |
| title_full_unstemmed | The laboratory calibration of a soil moisture capacitance probe in sandy soils |
| title_short | The laboratory calibration of a soil moisture capacitance probe in sandy soils |
| title_sort | laboratory calibration of a soil moisture capacitance probe in sandy soils |
| topic | particle size distribution regression analysis relative density soil water monitoring volumetric water content |
| url | https://swr.agriculturejournals.cz/artkey/swr-202002-0002_the-laboratory-calibration-of-a-soil-moisture-capacitance-probe-in-sandy-soils.php |
| work_keys_str_mv | AT marinacampora thelaboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT annapalla thelaboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT ilariagnecco thelaboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT rossellabovolenta thelaboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT robertopassalacqua thelaboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT marinacampora laboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT annapalla laboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT ilariagnecco laboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT rossellabovolenta laboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils AT robertopassalacqua laboratorycalibrationofasoilmoisturecapacitanceprobeinsandysoils |