Relatiohship between Reference Evapotranspiration and some Climatic Parameters for Umudike, Nigeria.

Abstract

Reference evapotranspiration, ETo, is important as it is used to determine the evaporative demand of the atmosphere. there is a need for continued studies to determine the reference evepotranspiration of different locations as well as its relationship with various climatic parameters for the prediction of water demands for human and ecological reasons. A study undertaken to determine the relationship between ETo, obtained using the Food and Agriculture Organization of United Nations, Penman-Monteith (FAO-56 PM) method, and some climatic data in Umudike, Nigerian environment are presented. The climatic parameters considered are solar radiation, sunshine hours and wind speed. The interactions of climatic parameters in the input variables of the ETo model, are also investigated. Simple linear regression analyses of the ETo and the climatic parameters of the study area were conducted, and correlation coefficients between the ETo and the climatic parameters were obtained to be +0.676 for solar radiation, +0.673 for sunshine hours, and -0.151 for wind speed. While the population regression coefficients were : +0.234 for solar radiation, +0.0274 for sunshine hours, and +0.0282 for wind speed. The R2 was 0.976 and the significance F value was 0.000639. The results obtained were compared with results of studies by other researchers and fitted well.