Comparison of Infiltration Pattern In Homogeneous Soil of Various Grain Sizes Based on The Water-Ponding Model
Reza Adhi Fajar (a,b*), Lilik Eko Widodo (c), Sudarto Notosiswojo (c), Gunawan Handayani (d), Aris Rinaldi (e)
a) Doctoral Study Program in Mining Engineering Department, Bandung Institute of Technology
Ganesha 10, Bandung 40132, Indonesia
b) Mining Department, Banjarmasin State Polytechnics, Kayutangi Banjarmasin 70124, Indonesia
*reza_af[at]students.itb.ac.id
c) Research Group of Earth Resources Exploration, Faculty of Petroleum and Mining, Bandung Institute of Technology
Ganesha 10, Bandung 40132, Indonesia
d) Research Group of Earth-physics and Complex-system, Faculty of Physics and Mathematics Sciences, Bandung Institute of Technology
Ganesha 10, Bandung 40132, Indonesia
e) Directorate General of Water Resources – Public Work & Housing Ministry, Jakarta, Indonesia
Abstract
Water infiltration phenomenon through ground surface into the vadose zone is often described by a water ponding model. The description has been presented by researchers, but less of them have illustrated infiltration into homogenous soil of various grain sizes. The aim of this study is to compare water content distribution and the speed of wetting zone in Silica Sand soil of various grain sizes based on the purely physical movement approach. In this study, an infiltration process was simulated in a precisely soil column apparatus, which was used as a physical model; it had a height of 50 cm and a diameter of 15 cm. The water content distribution was illustrated by using numerical simulation based on Richards equation that was solved by finite different method with Crank-Nicolson scheme. Meanwhile, the function of water retention curve of the soil was predicted following van Genuchten parameters from measured logarithmic scale of negative soil water tension and water content values. The simulation results indicated that the speed of wetting fronts is decreased proportionately between soil size and ponding time that are apparent by means of comparison in logarithmic pattern. This simulation was refining the previous water-ponding model of natural sand, silt and clay soils.
Keywords: infiltration; water-ponding; water-content; soil-column; soil-water
Topic: International Symposium of Civil, Environmental, and Infrastructure Engineering