Projection of reference evapotranspiration over Ondo State using an ensemble of climate models

Abstract

Reference evapotranspiration (ETo) is a significant component of the hydrological cycle useful to develop integrated water resources management (IWRM). Climate change may have potential effects on ETo over Ondo State. It is essential to determine uncertainties in ETo for designing future water-holding structures and projecting crop water requirements (CWR). The sensitivity analysis over the study area indicated that an ensemble of six general circulation models (GCMs) from the 5th Coupled Model Intercomparison Project (CMP5) under Representative Concentration Pathways (RCP 4.5) projected increases in maximum and minimum temperatures (Tmax and Tmin) for the 2050s (2035-2065) and 2080s (2070-2100). The simulation run outputs showed that the projected ETo increased for the periods 2050s and 2080s in response to the baseline period (1975-2005), with larger increases in the 2080s. Generally, the predicted increases in ETo over Ondo State could be attributed to the expected increases in Tmax and Tmin.