Numerical and Experimental Analyses of a Sandy Soil Water Movement under a Point Source Using Dynamic Pore Network Modeling

Abstract

Water flow simulation in porous medium such as soil is an important topic in several branches of hydrology, soil science and agricultural engineering. In the present study, numerical results from a dynamic pore network model were used to determine a macroscopic relationship
between capillary pressure and fluid saturations. Then using the resulted relationship from pore network modeling and solving the partial differential Richards' equation by finite difference scheme (PNMCRE), water movement in the soil has been simulated. Also, soil water
movement was investigated by laboratory experiments on sandy soil. The performance of PNMCRE was evaluated by comparing the simulated wetting fronts with both of the observed patterns and those simulated by HUDRUS software package. Statistical analysis showed that
PNMCRE model with minimum errors and high correlation coefficients for all discharge rates and in time intervals had a better agreement with observed patterns in comparison with HYDRUS 2D