scholarly journals Estimation of the Hydrodynamic Parameters of Soils Subjected to Water Scarcity: Application of BEST and Introduction of a Specific Methodology

2021 ◽  
pp. 123-135
Author(s):  
Marco Aurélio Calixto Ribeiro De Holanda ◽  
Diogo Botelho Correa De Oliveira ◽  
Willames de Albuquerque Soares
Keyword(s):  
Hydraulic Conductivity ◽  
Sandy Soil ◽  
Water Scarcity ◽  
Hydrodynamic Characteristics ◽  
Soil Parameters ◽  
Specific Method ◽  
Capillary Length ◽  
Hydrodynamic Parameters ◽  
Characteristic Radius ◽  
Hydrus 1D

Propose a specific method (Junction Between Arya and Heitman and Haverkamp - JAHH), similar to BEST, to obtain the hydrodynamic parameters of soils in Pernambuco, Brazil. Sample: Department of Civil Engineering, Polytechnic School of Pernambuco – POLI, between March 2019 and February 2021. For this, BEST and JAHH were used to obtain the hydrodynamic characteristics of the collected materials, and the results of both methods were compared with simulations performed in Hydrus-1D. Sorptivity and Ks, acquired using both methods, presented differences reached 68.38% regarding Ks. The characteristic radius of the pores (λm) and capillary length (λc) obtained with BEST are not coherent, and this can be explained because during the evaluation of one sandy soil, λm values were the highest and λc were the lowest, when the opposite was expected. The use of JAHH to estimate soil parameters could generate more coherent estimates than BEST-slope, even though both of them have presented results of the same proportion, such as sorptivity and saturated hydraulic conductivity, for exemple. Therefore, the proposed method presented more pertinent results when compared to BEST regarding the studied soils.

scholarly journals Estimating the macroscopic capillary length from Beerkan infiltration experiments and its impact on saturated soil hydraulic conductivity predictions

2020 ◽  
Vol 589 ◽  
pp. 125159 ◽  
Author(s):  
Simone Di Prima ◽  
Ryan D. Stewart ◽  
Mirko Castellini ◽  
Vincenzo Bagarello ◽  
Majdi R. Abou Najm ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Soil ◽  
Capillary Length ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic

scholarly journals EFFECTS OF COMPACTION DUE TO MACHINERY TRAFFIC ON SOIL PORE CONFIGURATION

2015 ◽  
Vol 39 (2) ◽  
pp. 408-415 ◽  
Author(s):  
Carlos Germán Soracco ◽  
Luis Alberto Lozano ◽  
Rafael Villarreal ◽  
Telmo Cecilio Palancar ◽  
Daniel Jorajuria Collazo ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Compaction ◽  
Total Porosity ◽  
Soil Parameters ◽  
Long Term Effects ◽  
Pore System ◽  
Severe Problem ◽  
Mechanized Agriculture ◽  
Dynamic Indicators

Soil compaction has been recognized as a severe problem in mechanized agriculture and has an influence on many soil properties and processes. Yet, there are few studies on the long-term effects of soil compaction, and the development of soil compaction has been shown through a limited number of soil parameters. The objectives of this study were to evaluate the persistence of soil compaction effects (three traffic treatments: T0, without traffic; T3, three tractor passes; and T5, five tractor passes) on pore system configuration, through static and dynamic determinations; and to determine changes in soil pore orientation due to soil compaction through measurement of hydraulic conductivity of saturated soil in samples taken vertically and horizontally. Traffic led to persistent changes in all the dynamic indicators studied (saturated hydraulic conductivity, K0; effective macro- and mesoporosity, εma and εme), with significantly lower values of K0, εma, and εme in the T5 treatment. The static indicators of bulk density (BD), derived total porosity (TP), and total macroporosity (θma) did not vary significantly among the treatments. This means that machine traffic did not produce persistent changes on these variables after two years. However, the orientation of the soil pore system was modified by traffic. Even in T0, there were greater changes in K0 measured in the samples taken vertically than horizontally, which was more related to the presence of vertical biopores, and to isotropy of K0 in the treatments with machine traffic. Overall, the results showed that dynamic indicators are more sensitive to the effects of compaction and that, in the future, static indicators should not be used as compaction indicators without being complemented by dynamic indicators.

scholarly journals Modification of sandy soil hydrophysical environment through bagasse additive under laboratory experiment

2015 ◽  
Vol 29 (1) ◽  
pp. 101-106 ◽  
Author(s):  
A.A. Abd El-Halim ◽  
Arunsiri Kumlung
Keyword(s):  
Hydraulic Conductivity ◽  
Laboratory Experiment ◽  
Bulk Density ◽  
Sandy Soil ◽  
Sandy Soils ◽  
Total Porosity ◽  
Dry Weight ◽  
Weight Basis ◽  
Control Treatment ◽  
Study Results

Abstract Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment

scholarly journals Extension of the Gardner exponential equation to represent the hydraulic conductivity curve

2019 ◽  
Vol 67 (4) ◽  
pp. 359-371
Author(s):  
Theophilo B. Ottoni Filho ◽  
Marlon G. Lopes Alvarez ◽  
Marta V. Ottoni ◽  
Arthur Bernardo Barbosa Dib Amorim
Keyword(s):  
Hydraulic Conductivity ◽  
Degrees Of Freedom ◽  
Goodness Of Fit ◽  
Exponential Model ◽  
Capillary Length ◽  
Macropore Flow ◽  
Exponential Equation ◽  
Van Genuchten Model ◽  
Conductivity Curve ◽  
Two Parameter

Abstract The relative hydraulic conductivity curve Kr(h) = K/Ks is a key variable in soil modeling. This study proposes a model to represent Kr(h), the so-called Gardner dual (GD) model, which extends the classical Gardner exponential model to h values greater than ho, the suction value at the inflection point of the Kr(h) curve in the log-log scale. The goodness of fit of GD using experimental data from UNSODA was compared to that of the MVG [two-parameter (Kro, L) Mualem-van Genuchten] model and a corresponding modified MVG model (MVGm). In 77 soils without evidence of macropore flow, GD reduced the RMSE errors by 64% (0.525 to 0.191) and 29% (0.269 to 0.193) in relation to MVG and MVGm, respectively. In the remaining 76 soils, GD generally was less accurate than MVG and MVGm, since most of these soils presented evidence of macropore flow (dual permeability). GD has three parameters and two degrees of freedom, like MVG. Two of them allow the calculation of the macroscopic capillary length, a parameter from the infiltration literature. The three parameters are highly dependent on the Kr(h) data measurement in a short wet suction range around ho, which is an experimental advantage.

scholarly journals ESTUDO DOS PARÂMETROS HIDRODINÂMICOS OBTIDOS EM ENSAIOS DE CAMPO EM ITABIRITOS BRANDOS DA PORÇÃO SUDOESTE DO QUADRILÁTERO FERRÍFERO, MG

2018 ◽  
Author(s):  
Daniele Costa de Mesquita ◽  
Júlia Cotta Maciel Dantas ◽  
Rodrigo Sérgio de Paula ◽  
Kênia Janete Guerra
Keyword(s):  
Hydraulic Conductivity ◽  
Structural Complexity ◽  
Pumping Test ◽  
Iron Formation ◽  
Secondary Porosity ◽  
Hydrodynamic Parameters ◽  
Tube Wells ◽  
Quadrilátero Ferrífero

O artigo consiste na caracterização dos parâmetros hidrodinâmicos de condutividade hidráulica (K), transmissividade (T) e coeficiente de armazenamento (S) para itabiritos brandos na porção sudoeste do Quadrilátero Ferrífero (QF), MG. O estudo de tais parâmetros é essencial para o conhecimento dos aquíferos, tanto com relação à sua localização como também em termos de qualidade e quantidade das águas. O K foi obtido matematicamente por meio da equação de HVORSLEV (1951) e pela análise gráfica, também pelo método de Hvorslev, no programa AquiferTest, a partir de dados do slug testes em piezômetros. T e S foram obtidos por ajustes gráficos no mesmo programa pelos métodos de Neuman e Boulton, e com base em testes de bombeamento em poços tubulares profundos. Nas análises de condutividade hidráulica, o método gráfico se mostrou mais eficiente e os valores obtidos são coerentes com os resultados de MOURÃO (2007) - indicando uma uniformidade desta característica do aquífero Cauê, em toda porção oeste do QF. Já os valores de T e S obtidos refletem a heterogeneidade e anisotropia do sistema aquífero, possivelmente relacionadas às regiões de confinamento e uma permeabilidade secundária, provavelmente associada ao controle estrutural do fluxo.Palavras Chave: Parâmetros hidrodinâmicos, Slug teste, teste de bombeamento, itabirito brandoAbstract:STUDY OF THE HYDRODYNAMIC PARAMETERS OF SOFT ITABIRITOS IN THE SOUTH-WEST PORTION OF QUADRILATERO FERRIFERO OBTAINED BY FIELDWORK SIMULATIONS. This paper is based on the characterization of the hydrodynamic parameters hydraulic conductivity (K), transmissivity (T) and storage (S) in soft itabiritos of the southwest portion of the Quadrilatero Ferrifero (QF), MG. The study of these parameters is essential to the knowledge about aquifers, in terms of localization, quantity and quality of the water. The K was calculated using Hvorslev’s method and obtained by slug tests data for piezometers in the AquiferTest software. On the other hand, T and S had their results achieved using Neuman and Bouton methods also through the AquiferTest. The results were acquired by slope adjusts in graphs and the basis for these adjustments were pumping tests in deep tube wells. Considering the hydraulic conductivity, the graphic analyses were more effective and the results show a uniformity of this feature over the west QF, being consistent with MOURÃO (2007) studies. T and S, in turn, display the heterogeneity and anisotropy of the Caue iron formation probably caused by confined areas and secondary porosity due to the local structural complexity. Keywords: Hydrodynamic parameters, Slug test, pumping test, soft itabirito.

scholarly journals SENSITIVITY OF THE HYDRUS-1D MODEL TO CHANGES IN HYDRODYNAMIC PARAMETERS IN YELLOW LATOSOL

2019 ◽  
Vol 12 (3) ◽  
pp. 467
Author(s):  
Marco Aurelio Calixto Ribeiro de Holanda ◽  
Willames De Albuquerque Soares ◽  
Simone Rosa da Silva ◽  
Diogo Botelho Correa de Oliveira
Keyword(s):  
Hydrodynamic Parameters ◽  
1D Model ◽  
Hydrus 1D

scholarly journals Numerical Modelling and Experimental Testing of the Hydrodynamic Characteristics for an Open-Frame Remotely Operated Vehicle

2020 ◽  
Vol 8 (9) ◽  
pp. 688
Author(s):  
Qian Li ◽  
Yu Cao ◽  
Boyang Li ◽  
David M. Ingram ◽  
Aristides Kiprakis
Keyword(s):  
Numerical Model ◽  
Experimental Testing ◽  
Offshore Structures ◽  
Nonlinear Flow ◽  
Navier Stokes ◽  
Effective Control ◽  
Hydrodynamic Characteristics ◽  
Remotely Operated Vehicle ◽  
Hydrodynamic Parameters ◽  
And Performance

The remotely operated vehicles (ROVs) are important to provide the technology support for both the traditional offshore structures and rapidly-growing renewable energy facilities during their full-lifecycles, such as site survey, installation, inspection, maintenance and repair. Regarding the motion and performance of a ROV, the understanding of its hydrodynamic properties is essential when exposing to the disturbances of wave and current. In this study, a numerical model is proposed within the frame of an open-source platform OpenFOAM. The hydrodynamics of the adopted ROV (BlueRov2) in its four principal degrees of freedoms (DOFs) is numerically simulated by a Reynolds-Averaged Navier-Stokes (RANS) solver. Meanwhile, an experimental test is carried out by using a novel technique on measuring the hydrodynamic forces and moments. To validate the numerical prediction methodologies, a set of systematic simulations of the ROV subjected to the disturbances caused by various flow conditions are performed. Comparing to the model test measurement, the numerical model proved to be reliable in offering a good estimation of the hydrodynamic parameters. This also indicates that the presented numerical methodologies and experimental techniques can be applied to other types of open-frame ROVs in quantifying the hydrodynamic parameters, capturing the physics of the fluid-structure interaction (FSI) and feature of the turbulent vorticity which are all essential for the effective control of the ROVs under the nonlinear flow disturbances.

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