Application of a high resolution Distributed Temperature Sensor in a physical model reproducing subsurface water flow

A distributed temperature optical fibre sensors system with a sub-centimetre spatial resolution has been incorporated in a sand-box model. Its function is monitoring the temperature field induced in the sand by a horizontal water flow with inflowing water maintained at a constant temperature higher than the room temperature. The setup has been designed to investigate the variations of the temperature field induced by internal erosion in a dike. The paper presents preliminary results concerning heat transfer in the intact sample, before internal erosion is triggered. The results show that, with the sensing system adopted, temperature mapping in a soil sample can be obtained with such a richness of detail which is not comparable with that achieved adopting a system of pointwise sensors.