scholarly journals Environmental effects of temperature rise and long periods without precipitation on soil processes – case study for southern Slovakia

2018 ◽  
Vol 50 (3) ◽  
pp. 273-287
Author(s):  
Luboš Jurík ◽  
Peter Halaj ◽  
Tatiana Kaletová ◽  
Józef Mosiej ◽  
Jozefína Pokrývková ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Environmental Effects ◽  
Temperature Rise ◽  
Extended Period ◽  
River Basin Management ◽  
Soil Processes ◽  
Soil Water Retention ◽  
Effects Of Temperature

Abstract Environmental effects of temperature rise and long periods without precipitation on soil processes - case study for southern Slovakia. The general purpose of the article is to evaluate the environmental effects of temperature rise and long periods without precipitation on soil processes in southern Slovakia. Observed climate change (increase in average temperature) can cause changes in the fertility of the soil, especially in the direction of faster mineralization of organic matter. As an example, very accurate measurements of air temperature, rainfall and water content in the soil profile to a depth of 1 m are used. The more specific objective of the study was to evaluate the formation of soil water retention resources under high temperature conditions and over 30 days without rainfall. Based on the measured values, they were created graphs for extended period of time without precipitation. The graph shows the average daily soil moisture in each layer, which is measured at the hydrological network of stations in operation by Centre of Excellence for Integrated River Basin Management at SUA in Nitra. The final evaluation for the stations Žirany and Dolné Naštice, soil water content is showing the vulnerability of crops due to changes in water content, especially in layers from 0.3 to 0.5 m.

scholarly journals Soil-water content characterisation in a modified Jarvis-Stewart model: A case study of a conifer forest on a shallow unconfined aquifer

2017 ◽  
Vol 544 ◽  
pp. 242-253 ◽  
Author(s):  
Adrien Guyot ◽  
Junliang Fan ◽  
Kasper T. Oestergaard ◽  
Rhys Whitley ◽  
Badin Gibbes ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Unconfined Aquifer ◽  
Conifer Forest

A new procedure for the determination of soil-water retention curves by continuous drying using high-suction tensiometers

2011 ◽  
Vol 48 (2) ◽  
pp. 327-335 ◽  
Author(s):  
S. D.N. Lourenço ◽  
D. Gallipoli ◽  
D. G. Toll ◽  
C. E. Augarde ◽  
F. D. Evans
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Retention ◽  
Soil Water Retention ◽  
Mass Measurements ◽  
Discrete Measurement ◽  
Wetting Process ◽  
High Suction

Soil-water retention curves (SWRCs) can be determined using high-suction tensiometers (HSTs) following two different procedures that involve either continuous or discrete measurement of suction. In the former case, suction measurements are taken while the sample is permanently exposed to the atmosphere and the soil is continuously drying. In the latter case, the drying or wetting process is halted at different stages to ensure equalization within the sample before measuring suction. Continuous drying has the advantage of being faster; however, it has the disadvantage that the accuracy of mass measurements (necessary for the determination of water content) is affected by the weight and stiffness of the cable connecting the HST to the logger. To overcome this problem, an alternative continuous drying procedure is presented in this paper in which two separate but nominally identical samples are used to obtain a single SWRC; one sample is used for the mass measurements, while a second sample is used for suction measurements. It is demonstrated that the new continuous drying procedure gives SWRCs that are similar to those obtained by discrete drying.

Retrieving soil-water retention curve at the wet part by remote sensing

2020 ◽  
Author(s):  
Zampela Pittaki-Chrysodonta ◽  
Per Moldrup ◽  
Bo V. Iversen ◽  
Maria Knadel ◽  
Lis W. de Jonge
Keyword(s):  
Remote Sensing ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Spectral Data ◽  
Water Retention ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve

<p>The soil water retention curve (SWRC) at the wet part is important for understanding and modeling the water flow and solute transport in the vadose zone. However, direct measurements of SWRC is often laborious and time consuming processes. The Campbell function is a simple method to fit the measured data. The parameters of the Campbell function have been recently proven that can be predicted using visible-near-infrared spectroscopy. However, predicting the SWRC using image spectral data could be an inexpensive and fast method. In this study, 100-cm<sup>3</sup> soil samples from Denmark were included and the soil water content was measured at a soil-water matric potential from pF 1 [log(10)= pF 1] up to pF 3. The anchored Campbell soil-water retention function was selected instead of the original. Specifically, in this function the equation is anchored at the soil-water content at pF 3 (θ<sub>pF3</sub>) instead at the saturated water content. The image spectral data were correlated with the Campbell parameters [θ<sub>pF3</sub>, and the pore size distribution index (Campbell b). The results showed the potential of remote sensing to be used as a fast and alternative method for predicting the SWRC in a large-scale.</p>

scholarly journals Investigation into water retention behaviour of deformable soils

2013 ◽  
Vol 50 (2) ◽  
pp. 200-208 ◽  
Author(s):  
Simon Salager ◽  
Mathieu Nuth ◽  
Alessio Ferrari ◽  
Lyesse Laloui
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Retention ◽  
Void Ratio ◽  
Degree Of Saturation ◽  
Retention Data ◽  
Soil Water Retention ◽  
Retention Behaviour ◽  
Wide Range ◽  
Water Retention Behaviour

The paper presents an experimental and modelling approach for the soil-water retention behaviour of two deformable soils. The objective is to investigate the physical mechanisms that govern the soil-water retention properties and to propose a constitutive framework for the soil-water retention curve accounting for the initial state of compaction and deformability of soils. A granular soil and a clayey soil were subjected to drying over a wide range of suctions so that the residual state of saturation could be attained. Different initial densities were tested for each material. The soil-water retention curves (SWRCs) obtained are synthesized and compared in terms of water content, void ratio, and degree of saturation, and are expressed as a function of the total suction. The studies enable assessment of the effect of the past and present soil deformation on the shape of the curves. The void ratio exerts a clear influence on the air-entry value, revealing that the breakthrough of air into the pores of the soil is more arduous in denser states. In the plane of water content versus suction, the experimental results highlight the fact that from a certain value of suction, the retention curves corresponding to different densities of the same soil are convergent. The observed features of behaviour are conceptualized into a modelling framework expressing the evolution of the degree of saturation as a function of suction. The proposed retention model makes use of the theory of elastoplasticity and can thus be generalized into a hysteretic model applicable to drying–wetting cycles. The calibration of the model requires the experimental retention data for two initial void ratios. The prediction of tests for further ranges of void ratios proves to be accurate, which supports the adequacy of formulated concepts.

Relationship of soil water retention characteristics and soil properties: a case study from the Colombian Andes

2020 ◽  
pp. 1-10
Author(s):  
Clara Roa García ◽  
Sandra Brown ◽  
Maja Krzic ◽  
Les Lavkulich ◽  
María Cecilia Roa-García
Keyword(s):  
Organic Matter ◽  
Soil Water ◽  
Water Retention ◽  
Management Practices ◽  
Principal Component ◽  
Total Carbon ◽  
Soil Types ◽  
Soil Water Retention ◽  
Colombian Andes

Differences in soil water retention (SWR) characteristics between soil types and the factors driving those differences provide important information for land management, particularly in regions such as the Colombian Andes, which have limited water-storage infrastructure and where soils provide plant-available water and other ecosystem services. The objective of this study was to explore relationships between SWR and physical, chemical, and mineralogical properties of Andisols and Inceptisols through a case study of two watersheds in the Colombian Andes. This study identified a complex relationship between total carbon (TC), short-range order (SRO) minerals, and SWR. Both soil types had high SWR, with volumetric water content at permanent wilting point between 39% and 53%. Principal component analysis showed association of SWR with TC, SRO minerals, and % clay in both soil types. The Andisols of this study were coarse textured, allophanic (rich in allophane and imogolite — up to 17% in the B horizon), and with up to 15% TC in the A horizon. In contrast, the Inceptisols were fine textured (>30% clay) and higher in ferrihydrite than the Andisols. The formation of organo-metallic complexes was observed in A horizons; however, TC was lower under pasture than forest in both soil types. The addition of organic matter to soils with SRO minerals, such as the soils of this study, may foster the formation of organo-metallic complexes, stabilize soil C, and enhance SWR. Consequently, both study sites may benefit from management practices that increase soil organic matter.

Methanotrophic production of extracellular polysaccharide in landfill cover soils

2001 ◽  
Vol 43 (6) ◽  
pp. 151-159 ◽  
Author(s):  
W. Chiemchaisri ◽  
J. S. Wu ◽  
C. Visvanathan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Methane Oxidation ◽  
Extended Period ◽  
Soil Surface ◽  
Batch Cultivation ◽  
Bench Scale ◽  
Oxidation Rates ◽  
Tropical Conditions

A bench-scale soil reactor was used to study methane oxidation and EPS production under tropical conditions. The study of pertinent environmental factors affecting EPS production was carried out by batch cultivation of methanotrophs. These factors included variations in temperature (20°C to 45°C), soil water content (5% to 33%), and the supply ratios of methane/oxygen. The bench-scale study revealed that excessive EPS was accumulating in an active methane oxidation zone located 5-45 cm below the soil surface of the reactor. The observed peak rates of oxidation could not be sustained over an extended period of time due to EPS accumulation. Results from the batch cultivation experiments confirmed the production of EPS in soils subject to methane oxidation. EPS production was found to correlate with methane oxidation rates which, in turn, were regulated by the variance of temperature and soil water content. A larger amount of EPS production was obtained at 30°C and 17% soil water content. Oxygen is required for methane oxidation; however, at high oxygen tension it may accelerate the production of EPS by methanotrophs causing limited oxygen diffusion and declining rates of methane oxidation.

Global mapping of volumetric water content at 10, 33 and 1500 kPa using the WoSIS global database

2021 ◽  
Author(s):  
Maria Eliza Turek ◽  
Gerard Heuvelink ◽  
Niels Batjes ◽  
Laura Poggio
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Retention ◽  
Spatial Prediction ◽  
Volumetric Water Content ◽  
Data Availability ◽  
Pedotransfer Functions ◽  
Soil Water Retention ◽  
Direct Mapping

<p>Soil water content is a key property for modelling the water balance in hydrological, eco-hydrological and agro-hydrological models. Currently available global maps of soil water retention are mostly based on pedotransfer functions applied to maps of other basic soil properties. We developed global maps of the volumetric water content at 10, 33 and 1500 kPa by direct mapping based on soil water content data derived from the WoSIS Soil Profile Database and covariates describing vegetation, terrain morphology, climate, geology and hydrology using the SoilGrids workflow. The preparation of the input soil data consisted of the verification of available volumetric water content data and conversion of gravimetric to volumetric data using measured and estimated bulk density. In total we had 9609, 41082 and 49224 soil water content observations at 10, 33 and 1500 kPa, respectively, and prepared around 200 covariates as candidate predictors. After covariates selection, model tuning and cross-validation and final model fitting for 3D spatial prediction, results were presented for the globe with uncertainty estimation. The results were also compared to other available global maps of water retention to evaluate differences between direct mapping against other types of approaches. Directly developing global maps of soil water content, with associated uncertainty, is a novel approach for this type of properties, and contributes to improving global soil data availability and quality.</p>

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