Open AccessSensitivity of Reference Evapotranspiration Computed with FAO CropWat 8.0 Model to Weather Input Variables During Two Irrigation Seasons in Kaduna, Nigeria
Author(s) -
N. E. Onwuegbunam,
Donatus Obiajulu Onwuegbunam,
Vivien Chikogu Ameso,
U. U. Emeghara,
E. J. Zakka
Publication year - 2020
Publication title -
nigerian journal of pure and applied sciences/nigerian journal of pure applied sciences
Language(s) - English
Resource type - Journals
eISSN - 2756-3928
pISSN - 2756-4045
DOI - 10.48198/njpas/20.b18
Subject(s) - evapotranspiration , wind speed , correlation coefficient , mathematics , sensitivity (control systems) , environmental science , sunshine duration , irrigation , relative humidity , meteorology , statistics , geography , agronomy , biology , ecology , electronic engineering , engineering
The sensitivity analysis of the Food and Agriculture Organization (FAO) CropWat 8.0 model is aimed atdetermining the dominant variable of the model in the study area. Hence, the sensitivity coefficient and thecorrelation of the reference evapotranspiration (ETo) in Afaka, Kaduna, Nigeria, with each of the climatic inputvariables of the model, namely, maximum temperature (Tmax), minimum temperature (Tmin), humidity (H), windspeed (WS) and sunshine hour (SSH), were evaluated. A perturbation method was used in the evaluation and thesensitivity coefficients were obtained in a decreasing order of 0.55, 0.42, 0.22, 0.09 and -0.08 for Tmax, WS, SSH,Tmin and H, respectively. Also, the correlation of ETo with each of the input parameters, irrespective of the others,show the following correlation coefficients, r; SSH (r = 0.8675), Tmax (r = 0.6979), Tmin (r = 0.6226), H (r = 0.19)and WS (r = 0.0742). Hence, radiation and temperature-based estimations of ETo were recommended as usefultools for ETo estimation in the face of limited or scarce data and are adaptable to areas with similar climatecharacteristics. This would also serve as a theoretical basis for future studies on the response of ETo to climaticchange in the study area and other areas with similar climate.