Modeling Soil Water and Solute Transport—Fast, Simplified Numerical Solutions

Abstract

near the soil surface, in response to biology, climate, and management (Gupta et al., 1991). Uptake of water Modeling of water and solute transport in soils is increasinglyand solutes by plants is another difficult area, and ongoimportant in hydrology and agriculture, but there remain many gaps ing research will change the modeling of these processes. and unresolved issues. One of these, the speed and robustness of numerical solutions, is important in large-scale and stochastic model-Not all progress, however, depends on better soil ing. A fast method was developed for solution of the Richards equation characterization and research into soil and plant profor water transport. Brooks-Corey soil hydraulic property descripcesses. There are many reports of modeling results in tions were used with water content as the dependent variable in the literature, but it is often difficult to assess their unsaturated regions and pressure head in saturated regions. Central general implications because of differing system paramtime weighting was used in unsaturated conditions to improve accueters and input variables and because a thorough analyracy and fully implicit weighting in saturated conditions to improve sis of sensitivity to uncertainties in parameters and instability. Water fluxes were calculated using matric flux potentials puts is often not given. Of course, such uncertainty combined with a novel spatial weighting scheme for the gravitational analysis is not easy, especially when it concerns patterns component. Flow across soil property interfaces was calculated bysuch as climatic variation (Janssen et al., 1994). In addiequating fluxes to and from the interface. Results on a test problem involving rainfall, surface ponding, evaporation, and drainage over

Impact of Infiltration Process Modeling on Soil Water Content Simulations for Irrigation Management

“…Varado et al [23] assessed the efficiency of Ross model by comparing it at a first step with two analytical solutions and at a second step with SIPAT model. The results of this study showed that Ross solution [10] is a robust and accurate solution while a finer discretization is required close to soil surface to improve the results of cumulative infiltration. Crevoisier et al [24] compared within their study the Ross model with a finite element based Hydrus 1D model to evaluate the accuracy, computing time and convergence quality.…”

“…Ross [10] proposed a fast and non-iterative solution to solve the Richards' equation. A common way of characterizing unsaturated flow is Richards' equation on its mixed form (Richards, 1931): [29] for retention function is given by the following formula:…”

“…Due to the non-linearity of the described process as well as the high soil hydraulic parameters requirements, the use of numerical solutions is considered as time consuming with some stability problems [8]. Despite the progress made for developing efficient numerical schemes joined with faster computers, the use of such numerical methods is still time consuming when implemented for large study areas [10].…”

“…Recently, a new fast non-iterative solution for the non-linear 1D Richards' equation has been proposed by Ross [10]. Several researchers have considered Ross solution as a numerical solution [10,23,24].…”

“…Several researchers have considered Ross solution as a numerical solution [10,23,24]. This solution allowed overcoming the limitations of other commonly used numerical solutions [23].…”