Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"van Genuchten"”.
-
Determinação da condutividade hidráulica não saturada de solos residuais com o permeâmetro Guelph e ensaios de laboratório
… com a sucção, através das fórmulas empíricas de VAN GENUCHTEN (1980) e GARDNER (1958). Por fim, os valores da condutividade hidráulica não saturada fornecidos pelo permeâmetro Guelph foram comparados com os obtidos no laboratório. Com exceção do solo 03, no qual as paredes do furo escavado para a …
-
Quantification of wildfire-induced perturbations to soil-water retention curves and their impact on rainfall runoff
… The SWRC is commonly described using the Van Genuchten equation, in which key parameters are the residual water content, θr, saturated water content, θs, the pore-size distribution index, n, and the inverse of the air-entry pressure head, α. To date, the degree to which SWRCs are perturbed …
-
Modeling transport of agricultural chemicals in a dual porosity system resulting from macropores
… in each of the two regions are based upon the van Genuchten-Mualem relationships. The developed model was in one- and two-space dimensions and it contained several improvements over the previously proposed one-dimensional conceptual flow and transport models.
-
Hydrodynamic characterisation of soil subsurface flows for water conservation purposes.
… out on it, making four samples on the whole. The Van Genuchten model of the soil water characteristics curve has been used for the verification of the experimental data. The volumetric soil water contents and soil matric potentials of the four samples are compared at different depths, which reveal …
-
Untersuchung der hydraulischen Bodeneigenschaften durch GPR: Analyse der Kapillarsaumreflexion durch numerische Simulationen
… wobei die Modelle von Brooks-Corey, van Genuchten und dessen vereinfachte Form mit m=1-1/n verwendet werden. Durch Benutzung von Informationen aus dem Zeitbereich und dem Frequenzbereich sind die Auswirkungen der Parameter unterscheidbar, die verschiedenen Parametrisierungsmodelle …
-
Measurement of Soil and Water-Quality Parameters to Understand Subsurface Transport Processes
… soil characteristic models such as the van Genuchten and Brooks and Corey models using measured soil moisture and capillary pressure data. Also, in recent years, there has been increasing interest in developing remote sensing tools to measure soil moisture at multiple scales. As part of …
-
Sistema de classificação dos solos baseado na estrutura do espaço poroso
… into consideration a parameterization of the van Genuchten equation for Aa. Simultaneously, we conceived a hydrophysical database for Brazilian soils as a support to the proposed methodological approach, allowing also the development of studies on pedotransfer functions for hydraulic …
-
Avaliação da influência de um agente repelente sobre as propriedades mecânicas e hidráulicas de um solo arenoso
… e repelente, utilizando-se o modelo de Mualen-van Genuchten acoplado à equação de Richards e implementado pelo método das diferenças finitas em planilhas eletrônicas.
-
Relaciones aire agua en sustratos de cultivo como base para el control del riego. Metodología de laboratorio y modelización
… de tercer grado) como semi-experimentales (Van Genuchten)- empleados en la bibliografía para describir la curva de retención de agua. Tanto en el desarrollo de la metodología de laboratorio como en el estudio del modelo se ha empleado una gama de sustratos de características muy diferentes …
-
An Evaluation of Borehole Hydraulic Conductivity Equations and Field Determined Soil Water Characteristic Curves
… pad. The obtained data were fitted using the van Genuchten model and the RETC (RETention Curve) program. </p> <p>The results that were obtained from TSB testing led to the conclusion that Method B and C, as written in the ASTMs D6391-11 standard contained errors that impacted the results that …
-
Rainfall-runoff control: variably saturated transport for an infiltration system controlling water quality and quantity
… by fitting gravimetric measurement data to the van Genuchten equation. Good agreement with experimental data supports the conceptual basis of the trajectory model with a combined gas-liquid interface adsorption term in addition to the straining, interception, and sedimentation mechanisms of the …
-
Effective properties of multiphase flow in heterogeneous porous media
… hetero geneity and for the Borden Aquifer, van Genuchten characterization reduces system anisotropy by several orders of magnitude. Anisotropy of the effective properties proved to be less sensitive to Leverett scaling if the Brooks-Corey characterization was used due to insensitivity in …
-
Infiltration Models for Engineered Media in Living Roofs and Bioretention
… Based on well fitted WRC functions, namely the van Genuchten and Durner functions, continuous uni- and bimodal pore size distributions for tested media were derived. The modeling of the infiltration processes of seven engineered media (either 10-cm or 100-cm depth) subjected to simulated large …
-
The Impact of a Planar Drainage Geocomposite in Unsaturated Soil
… models and their related K-function predictions (van Genuchten 1980, Fredlund and Xing 1993, and Fredlund, Xing and Huang 1994) were evaluated against the measured GWCC and K-functions. Both the van Genuchten (1980) and Fredlund and Xing (1993) formulations for curve-fitting were found to be …
-
Modeling fluid imbibition for hydraulic fracturing and its implications on unconventional hydrocarbon recovery
… model is presented, which captures various relevant physical mechanisms. Specifically, the rock matrix is conceptualized as a combination of semi-permeable membrane-like components and non-membrane components and the osmosis membrane efficiency term is redefined to properly simulate osmosis …
-
Experimental and numerical analysis of behaviour of the myxospermous seeds of Capsella bursa-pastoris (L.) Medik. (shepherd’s purse) in soil
… The water retention curve of soil was fitted by van Genuchten model and their fitted parameters were used in numerical modelling later. The mucilage or seeds had greater influence on sandy-loam soil compared with clay type soil, both the water retention and the rheology properties. It was also …
-
Development of a technical management tool for settlement and stability behaviour of municipal solid waste landfills
… including the gas diffusion coefficient and the van Genuchten parameter have trivial effects when compared to their relevant normal operating point (NOP). However, some other parameters have different degree of impact on the landfill settlement. In this research, a numerical study has also been …
-
Stanovení hydraulických charakteristik půdy ve vybrané lokalitě
Diplomová práce se zabývá přímým a nepřímým stanovením hydraulických charakteristik půdy, tj. retenční čára a hydraulická vodivost, v lokalitě Bohaté Málkovice. Pro laboratorní stanovení vlhkostní retenční křivky půdy se používá pískový tank a přetlakový přístroj. K nepřímému určení hydraulických …