Rate of infiltration for different soil textures using rainfall simulator and Green–Ampt model

This paper presents the result of a study carried in Guwahati, aimed to compare the rate of infiltration determined for the different types of soil textures collected from different location by using numerical model and physical model. The Green–Ampt (GA) model is widely used in hydrologic studies as a simple, physically based method to estimate infiltration process. In this study, GA model is used to estimate rate of infiltration for the soil textures. The physical model is designed to measure the rate of infiltration of simulated rainfall for the soil textures. A portable rainfall simulator is constructed in the laboratory as a physical model to measure the rate of infiltration. The estimated infiltration rate helps in designing of irrigation systems, in the determination of availability of water for plant, runoff, percolation and for accurate determination of surface runoff. The soil textures are identified as sample 1 (clay) and the rates of infiltration obtained from the numerical and physical model are as 0.5794 and 0.2536 cm/h, sample 2 (Loamy sand) are 4.0432 and 3.0443 cm/h and sample 3 (sandy loam) are 2.2691 and 1.7961 cm/h, respectively. The results of both the models are compared and discussed, and the useful conclusions are drawn. © 2019 Indian Society for Hydraulics.