Review and validation of the average annual potential evapotranspiration (ETP) and monthly average in Honduras obtained for environmental remote sensing methods

Abstract

Evapotranspiration (ET) is an essential process in the planet's hydrologic cycle, and a very important estimation for water balance, especially in irrigation. Potential Evapotranspiration (PET) is the measure of the maximum ET possible in optimal conditions, its assessment is complex and empirical equations all over the world have been done to this purpose. In Honduras few works have been done about PET's estimation using empirical methodologies, applying usually the one with less data requirements. Using double mass and statistical test analysis have been verified that average temperature is not a reliable record in most of the meteorological stations in the country.

For that reason, the PET estimation is more complicated. Recently, an alternative to empirical estimation has been published: Global Potential Evapotranspiration Map (Global-PET) based on Hargreaves method to PET´s evaluation, generated by Consortium for Spatial Information (CGIAR-CSI).

It has been statistically proved that Global-PET represents PET's annual and monthly variability using Hargreaves method, except September. There is also a gradient (-32 mm per each 100 meters of elevation) between PET and elevations above 150 m. Global-PET maps represent a new reliable, checked and validated database at national level, without any cost and accessible on internet for those who may want to use it for non commercial purpose.

DOI: http://dx.doi.org/10.5377/rct.v0i14.1797

Revista Ciencia y Tecnología No. 14, junio 2014: 77-98