Continuous Measurement of Surface Temperature using UAV in Small Bare Mountainous Catchment and Comparison with Radiation and Soil Water Content

Abstract

 The surface temperature distribution in mountain scale is important in various fields such as hydrological processes, plant ecology, snow and ice fields, but its observation is difficult in high temporal and spatial resolution inside 1 km² catchment. In this study, surface temperature distribution was observed by UAV with 1 hour and around 20 cm resolution in bare catchment, where influence of trees is negligible. In order to explain its distribution, soil moisture were observed at 26 points and in situ measurement was performed at one point in 10 minutes and the radiation balance was calculated considering the topography effect to examine the factor of ground surface temperature. As a result, the effect of slope orientation was large and showed a high correlation with net radiation and surface temperature. However, the correlation with soil water content was low. It would be because the influence of water content is small geologically, and locality of the soil moisture was high in field observation.