Observatorio de I+D+i UPM

Memorias de investigación
Ponencias en congresos:
Percolation in soils at Different Bulk Densities: Porosity, Connectivity and Grey Threshold
Año:2011
Áreas de investigación
  • Física química y matemáticas,
  • Ingenierías
Datos
Descripción
To improve percolation modelling on soils the geometrical properties of the pore space must be understood; this includes porosity, particle and pore size distribution and connectivity of the pores. A study was conducted with a soil at different bulk densities based on 3D grey images acquired by X-ray computed tomography. The objective was to analyze the effect in percolation of aspects of pore network geometry and discuss the influence of the grey threshold applied to the images. A model based on random walk algorithms was applied to the images, combining five bulk densities with up to six threshold values per density. This allowed for a dynamical perspective of soil structure in relation to water transport through the inclusion of percolation speed in the analyses. To evaluate separately connectivity and isolate the effect of the grey threshold, a critical value of 35% of porosity was selected for every density. This value was the smallest at which total-percolation walks appeared for the all images of the same porosity and may represent a situation of percolation comparable among bulks densities. This criterion avoided an arbitrary decision in grey thresholds. Besides, a random matrix simulation at 35% of porosity with real images was used to test the existence of pore connectivity as a consequence of a non-random soil structure. The results showed that porosity distribution with depth had the greatest oscillations for the smallest density, while random matrix presented a scattered distribution around the 35% mean due to the lack of structure. Random matrix presented a normal distribution of percolation speed. In general, percolation speed for real images diminished with bulk density for total percolation walks. The simulated percolation speed for these images were not distributed according to a Gaussian curve, so it was not possible to assume the Darcy's Law to explain percolation in these soils.
Internacional
Si
Nombre congreso
AGU Fall Meeting 2011
Tipo de participación
960
Lugar del congreso
San Francisco, USA
Revisores
Si
ISBN o ISSN
0096-3941
DOI
Fecha inicio congreso
05/12/2011
Fecha fin congreso
09/12/2011
Desde la página
1303
Hasta la página
1303
Título de las actas
AGU Fall Meeting Abstracts Vol.H
Esta actividad pertenece a memorias de investigación
Participantes
  • Autor: Margarita Ruiz Ramos (UPM)
  • Autor: Daniel del Valle (UCLM)
  • Autor: P. Baveye (University of Abertay, Dundee)
  • Autor: Ana Maria Tarquis Alfonso (UPM)
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Grupo de Automatización en Señal y Comunicaciones (GASC)
  • Centro o Instituto I+D+i: Centro de Estudios e Investigación para la Gestión de Riesgos Agrarios Medioambientales (CEIGRAM)
  • Grupo de Investigación: Grupo de Sistemas Agrarios (AgSystems)
  • Departamento: Producción Vegetal: Fitotecnia
  • Departamento: Matemática Aplicada a la Ingeniería Agronómica
S2i 2021 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)