| Abstrakt: |
Evapotranspiration is an important part in surface energy balance and water balance. Compared with other methods (micrometeorological, climatological, or hydrological method), the remote sensing model has obvious superiority to estimate regional evapotranspiration over heterogeneous surfaces. In this study, based on Landsat TM/ETM+ data and meteorological data, evapotranspiration in Beijing area on 17 April 2001, 12 April 2002, 06 July 2004, 06 May 2005, and 22 May 2005 were calculated by an estimation model of regional evapotranspiration. Comparisons of energy balance components (net radiation, soil heat flux, sensible and latent heat flux) with measured fluxes were made integrating the remotely sensed fluxes by the footprint model. Results show that latent heat flux estimates (adjusted for closure) with errors (MBE±RMSE) 26.47±42.54 Wm-2, sensible heat flux error of -8.56±23.79 Wm-2, net radiation error of 25.16±50.87 Wm-2 and soil heat flux error of 10.68±22.81 Wm-2. The better agreement between the estimates and the measurements indicates that the remote sensing model is appropriate for estimating regional evapotranspiration over heterogeneous surfaces. Furthermore, the spatial distribution of evapotranspiration in Beijing area was analyzed. [ABSTRACT FROM AUTHOR] |
