COMPARATIVE PERFORMANCE ASSESSMENT OF SELECTED INFILTRATION MODELS FOR HYDROLOGICAL MODELING IN OWERRI IMO STATE, NIGERIA

Abstract

Infiltration plays a critical role in hydrological modeling and irrigation system design, especially in regions with varying soil conditions and water management challenges. This study examines and evaluates the performance of three widely used infiltration models; Horton, Philip, and Green-Ampt using field data collected from Owerri North and Owerri West in Imo State, Nigeria. Soil analysis included particle size distribution, specific gravity, and moisture content. Infiltration rates were measured using a double-ring infiltrometer. Statistical tools such as coefficient of determination (R2), root mean square error (RMSE), and T-test were employed for model evaluation. Results indicated that the Green-Ampt Model offered the best predictive performance at both Orji and Ihiagwa, with closer agreement to measured infiltration rates, followed by the Philip model. Horton’s model consistently over-predicted infiltration.  The research emphasizes the importance of site-specific model selection in hydrological modelling for improved water resource management.