Estimation of Soil Salinity Under Various Soil Moisture Conditions Using Laboratory Based Thermal Infrared Spectra

2020 ◽  
Author(s):  
Lu Xu ◽  
Zhichun Wang ◽  
Jinshan Hu ◽  
Shuguo Wang ◽  
John Maina Nyongesah
Keyword(s):  
Soil Moisture ◽  
Infrared Spectra ◽  
Soil Salinity ◽  
Thermal Infrared ◽  
Moisture Conditions

Retrieval of an Available Water-Based Soil Moisture Proxy from Thermal Infrared Remote Sensing. Part I: Methodology and Validation

2009 ◽  
Vol 10 (3) ◽  
pp. 665-683 ◽  
Author(s):  
Christopher R. Hain ◽  
John R. Mecikalski ◽  
Martha C. Anderson
Keyword(s):  
Soil Moisture ◽  
Potential Evapotranspiration ◽  
Thermal Infrared ◽  
Surface Energy Budget ◽  
Rooting Depth ◽  
Thermal Infrared Remote Sensing ◽  
Water Fraction ◽  
Available Water ◽  
Oklahoma Mesonet ◽  
Moisture Conditions

Abstract A retrieval of available water fraction ( fAW) is proposed using surface flux estimates from satellite-based thermal infrared (TIR) imagery and the Atmosphere–Land Exchange Inversion (ALEXI) model. Available water serves as a proxy for soil moisture conditions, where fAW can be converted to volumetric soil moisture through two soil texture dependents parameters—field capacity and permanent wilting point. The ability of ALEXI to provide valuable information about the partitioning of the surface energy budget, which can be largely dictated by soil moisture conditions, accommodates the retrieval of an average fAW over the surface to the rooting depth of the active vegetation. For this method, the fraction of actual to potential evapotranspiration ( fPET) is computed from an ALEXI estimate of latent heat flux and potential evapotranspiration (PET). The ALEXI-estimated fPET can be related to fAW in the soil profile. Four unique fPET to fAW relationships are proposed and validated against Oklahoma Mesonet soil moisture observations within a series of composite periods during the warm seasons of 2002–04. Using the validation results, the most representative of the four relationships is chosen and shown to produce reasonable (mean absolute errors values less than 20%) fAW estimates when compared to Oklahoma Mesonet observations. Quantitative comparisons between ALEXI and modeled fAW estimates from the Eta Data Assimilation System (EDAS) are also performed to assess the possible advantages of using ALEXI soil moisture estimates within numerical weather predication (NWP) simulations. This TIR retrieval technique is advantageous over microwave techniques because of the ability to indirectly sense fAW—and hence soil moisture conditions—extending into the root-zone layer. Retrievals are also possible over dense vegetation cover and are available on spatial resolutions on the order of the native TIR imagery. A notable disadvantage is the inability to retrieve fAW conditions through cloud cover.

Soil salinity monitoring and detection of obstructed drainage pipes in the B-XII irrigation district (SW Spain) using electromagnetic induction sensing and inversion. 

2021 ◽  
Author(s):  
Mario Ramos ◽  
Mohhamad Farzamian ◽  
José Luis Gómez ◽  
Alfonso González ◽  
Benito Salvatierra ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Drainage System ◽  
State Agency ◽  
Irrigation District ◽  
Sw Spain ◽  
Hard Soil ◽  
Moisture Conditions ◽  
And Inversion

<p>Inversion of electromagnetic induction (EMI) signals is increasingly used for monitoring soil salinity in irrigated fields. In the B-XII irrigation district (SW Spain) the build-up of high salt concentrations in the topsoil is often related with a deficient performance of the underlying drainage system resulting in higher-than-average soil moisture conditions and salinization. This work aims at using EMI sensing and inversion to identify and localize problems (<em>e.g</em>. obstruction) with the drainage system in a 12.5 ha irrigated field in the B-XII irrigation district. The identified salinity hotspots in the EMI images are further validated using remotely sensed NDVI data and detailed information obtained during the cleaning of the drainage system, in addition to hard soil data. This study shows that EMI sensing and inversion can pinpoint problems with the drainage system that result in salinity hotspots and identify areas where the drainage system should be cleaned or substituted.</p><p> </p><p>This work is funded by the Spanish State Agency for Research through grants PID2019-104136RR-C21 and PID2019-104136RR-C22 and by IFAPA/FEDER through grant AVA2019.018.</p>

CONVERSION OF ELECTROMAGNETIC INDUCTANCE READINGS TO SATURATED PASTE EXTRACT VALUES IN SOILS FOR DIFFERENT TEMPERATURE, TEXTURE, AND MOISTURE CONDITIONS

1989 ◽  
Vol 69 (1) ◽  
pp. 25-32 ◽  
Author(s):  
R. C. McKENZIE ◽  
W. CHOMISTEK ◽  
N. F. CLARK
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Key Words ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Linear Equations ◽  
Temperature Correction ◽  
Available Soil Moisture ◽  
Moisture Conditions

Linear equations were developed for converting electromagnetic induction readings (ECa) from EM38 meters to saturated paste electrical conductivity values (ECc). To correlate EM38 readings with measured ECe values, field sites representing a range of salinity conditions were sampled in 0.30-m increments to a depth of 1.5 m. Adapting a weighting procedure based on the EM38 meter's response to depth, ECe values were condensed into a single weighted value. The weighted ECe values were linearly correlated with temperature-corrected ECa readings. Equations were designed for soils of various textures under varying temperature and moisture conditions. For accurate ECa to ECe conversions, soil temperature correction of ECa is essential. When a frozen layer is present, EM38 readings are unreliable. EM38 horizontal and vertical modes show different ECa readings for the same depth-weighted ECe. Variability of ECa to ECe conversion was greater on coarse-textured than medium- or fine-textured soils. Available soil moisture should be above 30% for accurate ECe determinations from ECa readings. Key words: Salinity methods, soil salinity, saturated paste extract method, electromagnetic inductance meters, soil temperature

Evaluation of Presswheels and Seed Coverers for Direct Seeding of Brassica

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 599E-600
Author(s):  
Regina P. Bracy ◽  
Richard L. Parish
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Visual Observation ◽  
Mustard Seed ◽  
High Soil Moisture ◽  
Loam Soil ◽  
Direct Seeded ◽  
Plant Emergence ◽  
Moisture Conditions ◽  
Determine Effect

Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.

Exploring the potential of soil moisture reanalysis data for improving the identification of regional landslide triggering thresholds

2021 ◽  
Author(s):  
Nunziarita Palazzolo ◽  
David J. Peres ◽  
Enrico Creaco ◽  
Antonino Cancelliere
Keyword(s):  
Soil Moisture ◽  
Rainfall Event ◽  
Rainfall Thresholds ◽  
Rainfall Duration ◽  
Soil Moisture Data ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
Different Depths ◽  
Moisture Conditions ◽  
Landslide Triggering

<p>Landslide triggering thresholds provide the rainfall conditions that are likely to trigger landslides, therefore their derivation is key for prediction purposes. Different variables can be considered for the identification of thresholds, which commonly are in the form of a power-law relationship linking rainfall event duration and intensity or cumulated event rainfall. The assessment of such rainfall thresholds generally neglects initial soil moisture conditions at each rainfall event, which are indeed a predisposing factor that can be crucial for the proper definition of the triggering scenario. Thus, more studies are needed to understand whether and the extent to which the integration of the initial soil moisture conditions with rainfall thresholds could improve the conventional precipitation-based approach. Although soil moisture data availability has hindered such type of studies, yet now this information is increasingly becoming available at the large scale, for instance as an output of meteorological reanalysis initiatives. In particular, in this study, we focus on the use of the ERA5-Land reanalysis soil moisture dataset. Climate reanalysis combines past observations with models in order to generate consistent time series and the ERA5-Land data actually provides the volume of water in soil layer at different depths and at global scale. Era5-Land project is, indeed, a global dataset at 9 km horizontal resolution in which atmospheric data are at an hourly scale from 1981 to present. Volumetric soil water data are available at four depths ranging from the surface level to 289 cm, namely 0-7 cm, 7-28 cm, 28-100 cm, and 100-289 cm. After collecting the rainfall and soil moisture data at the desired spatio-temporal resolution, together with the target data discriminating landslide and no-landslide events, we develop automatic triggering/non-triggering classifiers and test their performances via confusion matrix statistics. In particular, we compare the performances associated with the following set of precursors: a) event rainfall duration and depth (traditional approach), b) initial soil moisture at several soil depths, and c) event rainfall duration and depth and initial soil moisture at different depths. The approach is applied to the Oltrepò Pavese region (northern Italy), for which the historical observed landslides have been provided by the IFFI project (Italian landslides inventory). Results show that soil moisture may allow an improvement in the performances of the classifier, but that the quality of the landslide inventory is crucial.</p>

Rainfall thresholds for the triggering of landslides considering previous soil moisture conditions (Asturias, NW Spain)

Landslides ◽  
2017 ◽  
Vol 15 (2) ◽  
pp. 273-282 ◽  
Author(s):  
Pablo Valenzuela ◽  
María José Domínguez-Cuesta ◽  
Manuel Antonio Mora García ◽  
Montserrat Jiménez-Sánchez
Keyword(s):  
Soil Moisture ◽  
Nw Spain ◽  
Rainfall Thresholds ◽  
Moisture Conditions
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