title: Remotely monitoring evaporation rate and soil water status using thermal imaging and "three-temperatures model (3T Model)" under field-scale conditions.
abstract: Remote monitoring of soil evaporation and soil water status is necessary for water resource and environment management. Ground based remote sensing can be the bridge between satellite remote sensing and ground-based point measurement. The primary object of this study is to provide an algorithm to estimate evaporation and soil water status by remote sensing and to verify its accuracy. Observations were carried out in a flat field with varied soil water content. High-resolution thermal images were taken with a thermal camera; soil evaporation was measured with a weighing lysimeter; weather data were recorded at a nearby meteorological station. Based on the thermal imaging and the three-temperatures model (3T model), we developed an algorithm to estimate soil evaporation and soil water status. The required parameters of the proposed method were soil surface temperature, air temperature, and solar radiation. By using the proposed method, daily variation in soil evaporation was estimated. Meanwhile, soil water status was remotely monitored by using the soil evaporation transfer coefficient. Results showed that the daily variation trends of measured and estimated evaporation agreed with each other, with a regression line of y = 0.92x and coefficient of determination R(2) = 0.69. The simplicity of the proposed method makes the 3T model a potentially valuable tool for remote sensing.
authors.affiliation: School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China. qiugy@szpku.edu.cn
authors.forename: Guo Yu
authors.initials: GY
authors.lastname: Qiu
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000465:Algorithms; D008956:Models, Chemical; D012987:Soil / Q000032:analysis*; D013696:Temperature; D014835:Volatilization; D014867:Water / Q000737:chemistry*
chemical_list: D012987:Soil; D014867:Water