Estimation of monthly FAO Penman-Monteith evapotranspiration in GIS environment, through a geometry independent algorithm

摘要

The purpose of this study was to implement the monthly FAO Penman-Monteith evapotranspiration estimation method in a G1S environment, given the importance of spatial estimation of the evapotranspiration in the rational management of water resources and also the lack of easily applicable methodology in GIS environment. In this context, a Python programming language script was developed for implementing monthly FAO Penman-Monteith evapotranspiration equation, in ESRI's ArcMap environment. This approachhas the advantage of being independent of the type of geospatial data and can be applied in point, line and polygon data while at the same time being flexible and time saving without loss of accuracy. The methodology was applied using meteorological data of the 2011 irrigation period (March to September), acquired from the meteorological station located at the campus of Technological Educational Institute of Western Greece at Messolonghi (38° 21' 58" N; 21° 28' 41" E), with the results being very satisfactory.