Field thermal infrared emissivity dependence on soil moisture

摘要

Emissivity dependence on soil water content has been already reported and modelled under controlled conditions in the laboratory. This study completes and extends that previous work by providing emissivity measurements under field conditions without elimination of impurities, local heterogeneities or soil cracks appearing in the drying process. A bare soil plot was selected in central Arizona, USA. The soil plot was flood irrigated every 2-3 days and left to dry. Field emissivity measurements were collected for different values of soil water content. An overall increase of emissivity with soil moisture was obtained. It was also shown that deterioration of the soil surface tends to reduce the emissivity spectral contrast. Relationships obtained by Mira et al. (2010) were tested and compared with the field measurements.