Modelling potential evapotranspiration of potential vegetation

摘要: Abstract A method to estimate the potential evapotranspiration (PET) rate of vegetation is presented. The based on Penman–Monteith equation which includes fixed parameters and variables height leaf area index (LAI). starting LAI value 0.2 used calculate height, aerodynamic resistance, canopy resistance finally, PET rate. successively increased by 0.1 calculation process repeated obtain corresponding values. When annual exceeds yearly available water reserves, cycle interrupted leading definitive LAI. evaporation rainfall intercepted plant soil are then added estimated in this manner. These turn vary according distribution Spanish peninsula calculated several methods represented maps may be easily compared. comparison with those published other authors was also undertaken. differed considerably from that reference crop (grass). In rainy areas (irrespective temperature) exceeded due canopy. dry areas, lower respect PET. This explained fact when small, transpiration rain consequently reduced. Furthermore, values obtained reasonably consistent characteristics vegetation. It proposed type use study climate general.