Estimation of Kostiakov’s Infiltration Model Parameters of Some Sandy Loam Soils of Ikwuano – Umuahia, Nigeria

Abstract

Infiltration equations are necessary in designing and evaluating surface irrigation systems. This paper applied the empirical kostiakov’s infiltration model on the sandy soils of Ikwuano -Umuahia ,in order to determine the infiltration model parameters of the soils. Field measurements of infiltration were made using a double ring infiltrometer during the wet season . Readings were taken at 5, 10, 15 and 30 minutes intervals. Infiltration rate ranged from 0.02cm/min to 0.88cm/min. Kostiakov’s infiltration model was then applied on the field data in order to determine the soils’ infiltration parameters and also to estimate the model equations for the soils. Infiltration equations estimated in this study were : I = 0.87t−0.54 , I = 0.35t−0.48 , I = 0.45t−0.62 , for points 1, 2 and 3 locations. Other were I = 1.63t−0.50 , I = 2.47t−0.84, I = 1.91t−0.59, and I = 1.79t−0.59 for the rest of the locations. kostiakov’s infiltration decay constants obtained were negative (-0.48, -0.50, 0.54, 0.59, 0.62 and 0.84), indicating that the soils were saturated at that time of the year. However, these equations obtained could be as an input data in irrigation design.