Browsing by Author "Iwuchukwu, Emmanuel Ikechukwu"

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    Modeling monthly relative humidity for evapotranspiration in Ohaji- Egbema, Imo State and Aninri, Enugu State
    (Federal University of Technology, Owerri, 2021-05) Iwuchukwu, Emmanuel Ikechukwu
    Monthly Relative humidity (RH) models for Enugu and Imo States were developed using statistical analysis (SPSS) based on stepwise method. In this study, the independent variables: sunshine hours, minimum temperature, maximum temperature, rainfall and vapour pressure and the dependent variable (monthly relative humidity) were obtained from Nigeria Meteorological Agency (NIMET) for the years 1991 to 2010. The data for 1991 – 2007 were used to develop the models. High coefficients of determination R2 = 0.845 and 0.753 for estimating monthly relative humidity for Enugu and Imo respectively were obtained during model building. The developed models were used to predict a monthly relative humidity value for the remaining three years using data obtained from NIMET from 2008-2010 that was not used in building the model. It was observed that the Imo model predicted fairly accurate, judging from the low percentage error in year 2008 got from the monthly RH that was not used in building the model; (ranging from 0.46 to 45.94) but for 2009 and 2010, the percentage errors were fairly higher than that predicted for year 2008 whereas that of the Enugu model predicted fairly accurate, judging from the low percentage error in year 2008 got from the monthly RH not used in building the model;(ranging from 0.59 to 32.42) and also for 2009 and 2010, the percentage errors were fairly accurate as that predicted for year 2008. Thus the smaller the percentage error values between measured and predicted results, the better the model developed. Blaney-Morin Nigeria(BMN) model was used as a test case because it dealt with Evapotranspiration estimation in Nigeria. By applying the two models into equation 1.1, The error margin for RH model for Enugu state used in Blaney Morin-Nigeria(BMN) gave 0.0295 – 0.1864 whereas the error margin for RH model for Imo state used in BMN gave 0.0312 – 0.1322. By applying the developed monthly relative humidity in BMN model to estimate the monthly evapotranspiration from 1991 to 2010 gave a high significant difference. These results are clear evidence of the test of goodness of fit of the models between predicted and measured parameters for monthly relative humidity for Imo and Enugu states using BMN.