RAINFALL-RUNOFF RELATIONSHIP AND MODEL DEVELOPMENT FOR IMO STATE NIGERIA
Understanding the rainfall-runoff relationship is critical for effective hydrological modeling and water resources management. This study examined the relationship between rainfall and runoff in Imo State, Nigeria, and developed a predictive regression model to estimate runoff based on rainfall data. Historical meteorological data (1984-2009) were collected from two gauging stations one in each state. Regression and fuzzy logic techniques were applied to establish the rainfall runoff relationship and evaluate their predictive accuracy. The regression model developed was Y = 3.02 + 14.96X with a coefficient of determination (R²) of 0.84, indicating a strong linear relationship. Comparisons between the regression and fuzzy approaches revealed relative errors of 21.07% and 13.40%, respectively, confirming the validity of the regression model for runoff prediction in the study area. The study concludes that locally developed regression models can effectively predict rainfall runoff dynamics under regional climatic conditions and support sustainable soil and water management.
Keywords: Rainfall runoff modeling, Regression analysis, Fuzzy logic, Hydrology
