Monitoring of water and heat transfer in the vadose zone of a carbonate formation: An example of an underground quarry in Gironde, France

This article studies the water and heat transfer in the vadose zone of a carbonate formation during three hydrological cycles (August 2001–May 2004). The application of the time domain reflectometry (TDR) method to determine the volumetric water content of porous rocks has been widely investigated. The study of more than 285 monthly point measurements of the rock water content during three hydrological cycles, distributed throughout an abandoned underground quarry in Gironde, France, shows a permanently undersaturated limestone (between 35% and 50%). Three periods of maximum volumetric water content correspond to the occurrence of three effective rainfall events. The phase lag and amplitude damping of the hydraulic and thermal signals with depth can be modelled and explained by the hydraulic and thermal properties of the porous medium in the unsaturated zone.