A simplified equation to estimate spatial reference evaporation from remote sensing-based surface temperature and local meteorological data

摘要

A simplified equation to estimate spatial reference evapotranspiration (ET{sub}(o_Ts)) from remote sensing-based surface temperature (T{sub}s) and local standard meteorological data is suggested. It is based on a parameterization of the meteorological conditions of the first few meters of the atmosphere through two parameters (a and b) which come from a simpler form of the Penman-Monteith equation: ET{sub}(O-TS)= aT{sub}s + b This approach is of local nature since the parameters a and b must be estimated for a given area from meteorological data. The spatial pattern and temporal evolution in ET{sub}(o_Ts) have been analyzed using 58 NOAA-AVHRR images from 1992 to 1996 in a flat, subhumid region in the center of the Buenos Aires province, Argentina. The modelled ET{sub}(o-Ts) has been compared with local measurements, and results indicate that the error of estimate is ±0.6 mm day{sup}(-1).