A Rank- Reduced Analysis of Runoff Components and Their Response Patterns to Basin Parameters in the Northern Basement Complex, Nigeria.

Abstract

Hydrological studies are still scanty in northern Nigerian basins. Runoff components have been discovered to have different response patterns to basin variables, hence lumping them together may be misleading. This study attempt to study response patterns of six hydrological parameters namely: surface flow, interflow and groundwater flow, the annual hydrograph was also separated into dry season flow, wet season flow and total runoff. Thirty hydro- climatic variables generated from 30 sub basins of the upper Kaduna catchment covering a period of 11 year (1979-1989) were used in this study.  Surface flow, interflow and groundwater flow were determined using a 3-component hydrograph separation procedure; and dry season, wet season and total runoff were defined climatologically. A total of 660 hydrographs were separated. Factor regression method was used to identify the most significant factors which explain each of these components. The results showed that these variables differ slightly from one flow type to the other. That paper concludes that lumping different flow types together will amount to generalization. There is need for caution in runoff and basin modelling; all these call for more studies.