scholarly journals Hydraulic conductivity and water retention in leptosols-regosols and saprolite derived from sandstone, Brazil

2011 ◽  
Vol 35 (4) ◽  
pp. 1253-1262 ◽  
Author(s):  
Fabrício de Araújo Pedron ◽  
Jessé Rodrigo Fink ◽  
Miriam Fernanda Rodrigues ◽  
Antonio Carlos de Azevedo
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Water Infiltration ◽  
Environmental Damage ◽  
Water Retention Capacity ◽  
Rio Grande Do Sul ◽  
Aquifer Contamination ◽  
Retention Capacity ◽  
Effective Depth ◽  
Plant Available Water

Leptosols and Regosols are soils with a series of restrictions for use, mainly related to the effective depth, which have been poorly studied in Brazil. These soils, when derived from sedimentary rocks should be treated with particular care to avoid environmental damage such as aquifer contamination. The purpose of this study was to verify the behavior of hydraulic conductivity and water retention capacity in profiles of Leptosols and Regosols derived from sandstone of the Caturrita formation in Rio Grande do Sul state. The morphology, particle size distribution, porosity, soil density (Ds), saturated hydraulic conductivity (Ks), basic water infiltration in the field (BI) and water retention were determined in soil and saprolite samples of six soil profiles. High Ds, low macroporosity and high microporosity were observed in the profiles, resulting in a low Ks and BI, even under conditions of sandy texture and a highly fractured saprolite layer. The variation coefficients of data of Ks and BI were high among the studied profiles and between replications of a same profile. Water retention of the studied soils was higher in Cr layers than in the A horizons and the volume of plant-available water greater and variable among A horizons and Cr layers.

scholarly journals Modeling the hydrophysical soil properties and comparative analysis for three systems of functions

2020 ◽  
Vol 175 ◽  
pp. 09016
Author(s):  
Vitaly Terleev ◽  
Roman Ginevsky ◽  
Viktor Lazarev ◽  
Aleksandr Nikonorov ◽  
Alexander Topaj ◽  
...  
Keyword(s):  
Porous Medium ◽  
Soil Moisture ◽  
Comparative Analysis ◽  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Water Retention ◽  
Field Measurements ◽  
Practical Significance ◽  
Water Retention Capacity ◽  
Retention Capacity

A functional description of the hydrophysical properties of the soil as a capillary-porous medium is presented. The described functions of water retention capacity and hydraulic conductivity of the soil have common parameters, which are interpreted within the framework of physical and statistical concepts. The practical significance of the proposed functions lies in the fact that the volume of labor-intensive field measurements necessary, for example, for modeling the dynamics of soil moisture, is significantly reduced. To identify the parameters of these functions, it is sufficient to use data only on the water retention capacity of the soil. The parameters identified in this way can be used to predict the ratio of the hydraulic conductivity of the soil to the moisture filtration coefficient. The presented system of the hydrophysical functions of the soil is compared with world analogues using literature data on soils of different texture.

Enhanced Mualem-Van Genuchten Approach for Estimating Relative Soil Hydraulic Conductivity

2015 ◽  
Vol 725-726 ◽  
pp. 355-360 ◽  
Author(s):  
Vitaly Terleev ◽  
Vladimir Badenko ◽  
Inna Guseva ◽  
Wilfried Mirschel
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Soil Characteristics ◽  
Water Volume ◽  
Water Retention Capacity ◽  
Moisture Capacity ◽  
Theoretical Justification ◽  
Retention Capacity ◽  
Relative Water ◽  
Relative Hydraulic Conductivity

New theoretical justification for the function of soil differential moisture capacity (dependence of the relative water volume content on the capillary pressure) and its antiderivative is presented. New method is based on the concept of capillarity and the lognormal distribution of the effective radii of pores. Relative hydraulic conductivity of soil is calculated with usage of these functions and Mualem's approach. Hydrophysical parameters have been interpreted and evaluated on the base of some physical and statistical soil characteristics. Also the approximation for functions of water-retention capacity and relative hydraulic conductivity of soil has been proposed.

scholarly journals Material Characteristics, Hydraulic Properties, and Water Travel Time through the Heterogeneous Vadose Zone of a Cenozoic Limestone Aquifer (Beauce, France)

2020 ◽  
Author(s):  
Arnaud Isch ◽  
Carlos Aldana ◽  
Yves Coquet ◽  
Mohamed Azaroual
Keyword(s):  
Hydraulic Conductivity ◽  
Water Flow ◽  
Vadose Zone ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Limestone Aquifer ◽  
Limestone Rock ◽  
Hydrus 1D

<p>Water retention and hydraulic conductivity are the most important properties governing water flow and solute transport in unsaturated porous media. However, transport processes in the vadose zone (VZ) are still not completely understood, in spite of their importance for the preservation and management of aquifers, especially in the geographic zones under intensive agriculture. This study has been carried out as part of the construction of the O-ZNS platform (Observatory of transfers in the vadose zone). This platform aims to integrate observations over a wide range of spatial and temporal scales thanks to a large access well (depth–20 m & diameter–4m) surrounded by several boreholes in order to combine broad characterization and focused monitoring techniques.</p><p>Three cored boreholes have been drilled in Spring 2017. Structural and mineralogical analyses were carried out for four types of materials sampled throughout the entire VZ profile (20 m depth) including soft sediments (soil, marl and sand) and fractured limestone rock. Hydraulic properties (q(h) and K(h)) were measured on representative core samples by means of a triaxial system used by applying the multistep outflow method. Simulations were then made using HYDRUS-1D to simulate water flow and bromide (conservative tracer) transport over 50 years using meteorological and water table level data.</p><p>The results brought valuable information about factors contributing to the heterogeneity of hydraulic properties within the VZ. For the applied matric heads (from 0 to -1000 cm), the water content and hydraulic conductivity of (i) the soft materials (9 samples) ranged from 0.173 to 0.485 cm<sup>3</sup>/cm<sup>3</sup> and from 1.26.10<sup>-5</sup> to 2.41 cm/d, respectively ; (ii) the hard materials (5 samples) ranged from 0.063 to 0.340 cm<sup>3</sup>/cm<sup>3</sup> and from 8.54.10<sup>-5</sup> to 1.82 cm/d, respectively. The shape of the water retention and hydraulic conductivity curves obtained for the soft sediments is strongly related to the physical properties of the material but also to the proportion and the nature of clay minerals. The soil material displayed the largest average water retention capacity due to the presence of smectite and kaolinite, indicating weathering and matrix transformation. The water retention capacity of the marl and sand materials was lower due to higher content in palygorskyte and calcite. The limestone rock materials displayed an important heterogeneity in their hydraulic properties. Mineralogical analysis helped understanding water flow pathways within the limestone aquifer. The non-altered matrix, that seemed impermeable at first sight, presented few thin microfractures where water probably accumulates. The altered matrix showed microfractures where water has circulated and calcite has been replaced by phyllosilicates, thus increasing the water retention capacity. Natura macrofractures observed at dm-scale showed the presence of iron oxides which highlighted an exposure to high water flow. Simulations made using HYDRUS-1D allowed a first estimation of water and solutes travel time through this highly heterogeneous vadose zone. The results highlighted transfer time of between 25 to 35 years for the bromide to reach water table. The differences observed between the three cored boreholes were mainly due to the heterogeneity of the marl materials located between 1 and 7 m deep.</p>

scholarly journals Do earthworms (D. veneta) influence plant-available water in technogenic soil-like substrate from bricks and compost?

2020 ◽  
Author(s):  
Susanne Ulrich ◽  
Moreen Willaredt ◽  
Thomas Nehls ◽  
Loes van Schaik
Keyword(s):  
Image Analysis ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Positive Influence ◽  
Water Retention Capacity ◽  
Microcosm Experiment ◽  
Retention Capacity ◽  
Before And After ◽  
Plant Available Water ◽  
Earthworm Activity

Abstract Purpose Topsoil and peat are often taken from intact rural ecosystems to supply the urban demand for fertile soils and soil-like substrates. One way of reducing this exploitation is to recycle suitable urban wastes to produce Technosols and technogenic soil-like substrates. In this study, we investigate the role earthworms can play in impacting the hydraulic properties of such a soil-like substrate. Materials and methods In a 4-month microcosm experiment, the influence of the earthworm species D. veneta on the hydraulic properties of brick-compost mixture was examined. Of the ten boxes filled with ca. 11 dm3 of ground bricks (0.7 cm3 cm−3) and green waste compost (0.3 cm3 cm−3), five contained earthworms (W-boxes) and the remaining five were used as controls (C-boxes). The substrate was periodically irrigated and the weight of the boxes and of the drained water was monitored. At the same time, images were taken from the front of the boxes to quantify the activity of the earthworms by image analysis and soil aggregation was studied with micrographs. Before and after the experiment, water retention curves were determined from disturbed samples of the substrate using the simplified evaporation method. Results and discussion After 6 weeks, differences between the C- and the W-boxes were evident. Micrographs showed brick-compost aggregates only for the substrates processed by earthworms. The earthworm activity leads to reduced evaporation and an increased water content in the respective microcosms. The effect persists even after disturbing the substrate. The proportion of plant-available soil water is about 0.02 cm3 cm−3 higher for the substrate processed by earthworms (0.250 ± 0.009 cm3 cm−3) compared with the control (0.230 ± 0.008 cm3 cm−3). Conclusions This study shows that earthworms are capable of ingesting and processing crushed bricks together with compost. The earthworms produced aggregates which persisted after disturbance and had a positive influence on the water retention capacity of such a soil-like substrate constructed from waste.

scholarly journals Effect of Unimodal and Bimodal Soil Hydraulic Properties on Slope Stability Analysis

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1674
Author(s):  
Hsin-Fu Yeh ◽  
Tsien-Ting Huang ◽  
Jhe-Wei Lee
Keyword(s):  
Hydraulic Conductivity ◽  
Slope Stability ◽  
Water Content ◽  
Water Retention ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Seepage Analysis ◽  
Hydraulic Behavior ◽  
Conductivity Function ◽  
The Impact

Rainfall infiltration is the primary triggering factor of slope instability. The process of rainfall infiltration leads to changes in the water content and internal stress of the slope soil, thereby affecting slope stability. The soil water retention curve (SWRC) was used to describe the relationship between soil water content, matric suction, and the water retention characteristics of the soil. This characteristic is essential for estimating the properties of unsaturated soils, such as unsaturated hydraulic conductivity function and shear strength. Thus, SWRC is regarded as important information for depicting the properties of unsaturated soil. The SWRC is primarily affected by the soil pore size distribution (PSD) and has unimodal and bimodal features. The bimodal SWRC is suitable for soils with structural or dual-porous media. This model can describe the structure of micropores and macropores in the soil and allow the hydraulic behavior at different pore scales to be understood. Therefore, this model is more consistent with the properties of onsite soil. Few studies have explored the differences in the impact of unimodal and bimodal models on unsaturated slopes. This study aims to consider unimodal and bimodal SWRC to evaluate the impact of unsaturated slope stability under actual rainfall conditions. A conceptual model of the slope was built based on field data to simulate changes in the hydraulic behavior of the slope. The results of seepage analysis show that the bimodal model has a better water retention capacity than the unimodal model, and therefore, its water storage performance is better. Under the same saturated hydraulic conductivity function, the wetting front of the bimodal model moves down faster. This results in changes in the pressure head, water content, and internal stress of the soil. The results show that the water content and suction stress changes of the bimodal model are higher than those of the unimodal model due to the difference in water retention capacity. Based on the stability of the slope, calculated using the seepage analysis, the results indicate that the potential failure depth of the bimodal model is deeper than that of the unimodal model.

Development of plant-available water in soil-like substrate derived from urban wastes and processed by earthworm Dendrobaena veneta

2020 ◽  
Author(s):  
Moreen Willaredt ◽  
Susanne Ulrich ◽  
Thomas Nehls ◽  
Loes van Scheik
Keyword(s):  
Image Analysis ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Positive Influence ◽  
Water Retention Capacity ◽  
Microcosm Experiment ◽  
Retention Capacity ◽  
Before And After ◽  
Plant Available Water ◽  
Earthworm Activity

<p>Topsoil and peat are often taken from intact rural ecosystems to supply the urban demand for fertile soils and soil-like substrates. One way of reducing this exploitation is to recycle suitable urban wastes to produce Technosols and technogenic soil-like sub­strates. In this study we investigate the role earthworms can play in improving the hydraulic properties of such a soil-like substrate.</p><p>In a four-month microcosm experiment, the influence of the earthworm species D.veneta on the hy­draulic properties of brick-compost mixture was examined. Of the ten boxes filled with ca. 11 dm³ of ground bricks (0.7 cm³ cm-3) and green waste compost (0.3 cm³ cm-3), five contained earthworms (W-boxes) and the re­maining five were used as controls (C-boxes). The substrate was periodically irrigated and the weight of the boxes and of the drained water was monitored. At the same time, images were taken from the front of the boxes to quantify the activity of the earthworms by image analysis. Before and after the experiment, water retention curves were determined from disturbed samples of the substrate using the simplified evaporation method.</p><p>After six weeks, differences between the C- and the W-boxes were evident. Micrographs showed brick-compost aggregates only for the substrates processed by earthworms. The earthworm activity leads to reduced evaporation and an increased water content in the respec­tive microcosms. The effect persists even after disturbing the substrate. The propor­tion of plant-available soil water is about 0.02 cm³ cm-3 higher for the substrate processed by earthworms (0.250 ±0.009 cm³ cm-3) compared to the control (0.230 ±0.008 cm³ cm-3).</p><p>This study shows that earthworms are capable of ingesting and processing crushed bricks together with compost. The earthworms produced aggregates which persisted after disturbance and had a positive influence on the water retention capacity of such a soil-like substrate constructed from waste.</p>

scholarly journals Evaluation of Substrate Hydraulic Properties Amended by Urea–formaldehyde Resin Foam

HortScience ◽  
2012 ◽  
Vol 47 (9) ◽  
pp. 1375-1381 ◽  
Author(s):  
Paraskevi A. Londra ◽  
Maria Psychoyou ◽  
John D. Valiantzas
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Urea Formaldehyde ◽  
Organic Soil ◽  
Organic Substrate ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Loam Soil

Urea–formaldehyde resin foam has been introduced as a synthetic organic soil amendment and is used in hydroponic systems, soilless cultures, production of container-grown plants, roof gardens, and sports fields. To evaluate whether urea–formaldehyde resin foam can improve physical properties (water retention capacity and aeration) of horticultural substrates, an organic substrate (coir) and an inorganic soil (loam soil) were selected and amended with urea–formaldehyde resin foam (Fytocell). Water retention curves, θ(h), saturated hydraulic conductivity, Ks, and the relationship between unsaturated hydraulic conductivity and volumetric water content, K(θ), were determined for Fytocell, coir, loam soil, mixtures of coir/Fytocell (60/40 v/v), and loam soil/Fytocell (60/40 v/v). Water retention curves indicated that the addition of Fytocell in loam soil and coir mixtures increased and decreased, respectively, the water retention capacity. The Ks of loam soil and coir mixtures were decreased and increased, respectively, by the addition of Fytocell. In all substrates studied, K(θ) decreased sharply when θ decreased from 0.80 to 0.20 m3·m−3. However, the coir/Fytocell mix had the highest values of K(θ) when θ was below 0.40 m3·m−3. Moreover, the comparison between estimated K(θ) values obtained using the experimental outflow method of Valiantzas (1989) and predicted values using the van Genuchten–Mualem model showed a satisfactory agreement (0.937 0.996) for the substrates examined.

scholarly journals Soil-hydrophysical information support of precise irrigation farming

2021 ◽  
Vol 2(26) ◽  
pp. 244-260
Author(s):  
V.V. Terleev ◽  
◽  
Ie. A. Dunaieva ◽  
R.S. Ginevsky ◽  
V.A. Lazarev ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Water Retention ◽  
Mathematical Formulation ◽  
Soil Layer ◽  
Water Retention Capacity ◽  
Hysteresis Phenomenon ◽  
Retention Capacity ◽  
Irrigation Rate ◽  
Relative Hydraulic Conductivity

The relevance of the study is determined by the demand for a physically adequate mathematical description of the interactions of water in the soil to develop a model of soil moisture dynamics as the intellectual core of resource-saving technologies for precise irrigation farming. The aim of the work is theoretical substantiation and mathematical formulation of the hydrophysical functions of the soil, taking into account hysteresis. A description of three systems of soil hydrophysical functions is given. To verify and compare the systems, computational experiments were carried out using both the package of original software and “3305 Ida silt loam (> 15 cm)” soil data from the authoritative literary source – the Mualem catalogue. The parameters of the functions were identified by the method of point approximation of the experimental data on the main branches of the hysteretic water-retention capacity. Using these parameters, we calculated (i) predictive estimates for the values of the function of relative hydraulic conductivity; (ii) scanning branches of the hysteretic water-retention capacity; (iii) precise irrigation rate. The hysteresis phenomenon is not typical for the hydraulic conductivity as a function of the volumetric water content in the soil. The original functions of System 3 are recommended for use. The advantages of the proposed method for calculating the precise irrigation rate are shown. The benefit of each system is that the functions forming this system, namely the water-retention capacity and the relative hydraulic conductivity of the soil, have a common set of parameters. For the type of soil considered, in case of using the identical value of pre-irrigation soil moisture (179 [cm3 · cm-3]), both for calculating the precision irrigation rate and according to the “traditional” method, when moistening 50 cm soil layer, the total unproductive water consumption at irrigation rate 555 [m3 · ha-1] can reach 0.029 [cm3 · cm-3] or 140 [m3 · ha-1] in the calculated layer. At the same time, when applying precision standards, an excess of free moisture is not formed. It shows additional opportunities not only to save water during irrigation, especially in arid regions, but also to reduce the leaching of nutrients and agrochemicals outside the calculated soil layer and, accordingly, to reduce the additional environmental load on the surrounding area.

scholarly journals Modeling of Hydrophysical Properties of the Soil as Capillary-Porous Media and Improvement of Mualem-Van Genuchten Method as a Part of Foundation Arrangement Research

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Vitaly Terleev ◽  
Aleksandr Nikonorov ◽  
Vladimir Badenko ◽  
Inna Guseva ◽  
Yulia Volkova ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Water Retention Capacity ◽  
Filter Coefficient ◽  
Theoretical Justification ◽  
Retention Capacity ◽  
Soil Hydraulic Conductivity ◽  
Water Capacity ◽  
Conductivity Function ◽  
Relative Hydraulic Conductivity

Within the concepts about the capillarity and the lognormal distribution of effective pore radii, a theoretical justification for function of differential water capacity and its antiderivative (function of water-retention capacity in form of a dependence of the soil volumetric water content on capillary pressure of the soil moisture) is presented. Using these functions, the ratio of soil hydraulic conductivity function to the filter coefficient is calculated. Approximations to functions describing the water-retention capacity and relative hydraulic conductivity of the soil have been suggested. Parameters of these functions have been interpreted and estimated with applying the physical and statistical indices of the soil.

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