Determination of the Evapotranspiration Parameters of Benin City Based on the Penman-Monteith Equation from 1979 to 2013

Abstract

Evapotranspiration comprising the Reference evapotranspiration (ETo) and the standard crop Actual Evapotranspiration (ETc) was computed for Benin City using the Penman-Monteith equation for a period spanning 35years. The standard crop used in this study was Cassava. The input data of the equation consisted of meteorological data which were obtained from research-based institutions and government agencies. The results showed that the average daily ETo was between 2.643 and 3.162mm/day while similar data for the ETc was between 3.500 and 4.300mm/day. Peak ETo and ETc occurred in the month of March while the lowest values of these evapotranspiration constituents occurred in the month November and January.