干旱区生态环境知识资源中心

The METRIC model (Mapping Evapotranspiration at high Resolution using Internalized Calibration) utilizes multi-band reflectance and variation in thermal emission from Landsat and other satellites to estimate evapotranspiration (ET) using a full surface energy balance. Because of the aerodynamic nature of sensible heat exchange, aerodynamic roughness must be tailored for complex terrain and sparse systems such as trees. Soil heat flux is adjusted for hot desert conditions to account for delamination of soil layers. Net radiation is computed in mountainous areas by considering impacts of cross-valley thermal emission differences related to aspect as well as view-angle of sky and terrain.