Comparative Analysis Of Methods Of Baseflow Separation Of Otamiri Catchment

The various approaches of separating baseflow from other streamflow components are hinged on their respective strengths and drawbacks with respect to the watershed considered. Little wonder therefore that this research work has ventured on some methods amongst multitude of emerged methods to establish the best methods of baseflow separation and henceforth address the strength and drawback dichotomy associated with the different baseflow separation methods. The examined methods of baseflow separation used in this work are conveniently categorized into five basic approaches of fixed interval sliding interval local minimum Baseflow Index and frequency analysis. Data for the analyses obtained from Otamiri River at Nekede were utilized for this study and daily recorded streamflow discharge data obtained from the historical records held at the libraries of the Anambra Imo River Basin Development Authority Owerri and the Nigerian National Meteorological Services. The results of the predictability of the stream flow from the estimated baseflow for all the methods used conformed as evident in the regression analysis and the results showed that the value of the coefficient of simple determination r2 was highest in the fixed interval method and least in the frequency analysis method which implies that the fixed interval method was the best method of separating the base flows for Otamiri stream.