Author:
Onwuegbunam N.E.,Onwuegbunam D.O.,Ameso V.C.,Emeghara U.U.,Zakka E.J.
Abstract
The sensitivity analysis of the Food and Agriculture Organization (FAO) CropWat 8.0 model is aimed at
determining the dominant variable of the model in the study area. Hence, the sensitivity coefficient and the
correlation of the reference evapotranspiration (ETo) in Afaka, Kaduna, Nigeria, with each of the climatic input
variables of the model, namely, maximum temperature (Tmax), minimum temperature (Tmin), humidity (H), wind
speed (WS) and sunshine hour (SSH), were evaluated. A perturbation method was used in the evaluation and the
sensitivity 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 useful
tools for ETo estimation in the face of limited or scarce data and are adaptable to areas with similar climate
characteristics. This would also serve as a theoretical basis for future studies on the response of ETo to climatic
change in the study area and other areas with similar climate.
Publisher
Nigerian Journal of Pure and Applied Sciences
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