Abstracto

Short Term Variability of the Thermal Diffusivity and Thermal Conductivity for a Porous Media

Carles M. Rubio

Soil thermal property data, especially as a function of water content, are currently not readily available. Demand for these data is, however, on the increase because of improvements in wider applications of soil heat and water transport models, as well as, of the vegetal growth studies. Most of these investigations were focused in sandy soils, clayed soils or peat horticultural substrates, due to the different properties and applications of each ones. Otherwise, in order to partly fill the thermal soil properties studies into other types of soils, we focused this work in the relation between thermal and hydraulic soil properties of a silty soil under laboratory conditions. Samples were obtained from Can Solé Road located in the Llobregat delta plain (NE of Spain), where frequently Cynara scolymus is cultivated. Small dual-needle sensors, employing the heat pulse methodology were used to measure the soil thermal diffusivity, specific heat capacity and thermal conductivity. One soil column with a specific design was used. The column was monitorized to determine the volumetric water content and matric potential, as well as, the thermal properties. To obtain these kinds of data a frequency domain probe and micro-tensiometer were used. Preliminar results obtained up to now allow a rather complete understanding of the relation between thermal and hydraulic properties at laboratory scale of the silty soils. Preliminary distributed water content and thermal data allowed investigating the variability of these properties and its relations between them for this type of soils.