Modeling one‐dimensional infiltration into very dry soils: 1. Model development and evaluation

Hills, R. G.; Porro, I.; Hudson, David; Wierenga, P. J.

doi:10.1029/wr025i006p01259

Cited by 184 publications

(147 citation statements)

References 16 publications

Supporting

Mentioning

138

Contrasting

Unclassified

Order By: Relevance

“…Because of a series of issues intrinsically related to the nature of the infiltration process, accurate numerical simulation of infiltration remains a challenge, and convergence and stability are continuing problems. Among these issues, we can list the presence of steep wetting fronts; the elliptic form of Richards' equation in saturated domains; the non-mass-conserving of algorithms solving for ; and the fact that -based algorithms cannot be applied to situations where parts of the domain are saturated [Milly, 1985[Milly, , 1988Hills et al, 1989;Kirkland et al, 1992]. Different finite difference algorithms were developed that deal with these issues [Klute, 1952;Hanks and Bowers, 1962;Rubin, 1968;Brandt et al, 1971;Neuman, 1972;Vauclin et al, 1979].…”

Section: Numerical Solutions Of the Infiltration Equationmentioning

confidence: 99%

Infiltration into soils: Conceptual approaches and solutions

Assouline

2013

Water Resources Research

208

115

View full text Add to dashboard Cite

[1] Infiltration is a key process in aspects of hydrology, agricultural and civil engineering, irrigation design, and soil and water conservation. It is complex, depending on soil and rainfall properties and initial and boundary conditions within the flow domain. During the last century, a great deal of effort has been invested to understand the physics of infiltration and to develop quantitative predictors of infiltration dynamics. Jean-Yves Parlange and Wilfried Brutsaert have made seminal contributions, especially in the area of infiltration theory and related analytical solutions to the flow equations. This review retraces the landmark discoveries and the evolution of the conceptual approaches and the mathematical solutions applied to the problem of infiltration into porous media, highlighting the pivotal contributions of Parlange and Brutsaert. A historical retrospective of physical models of infiltration is followed by the presentation of mathematical methods leading to analytical solutions of the flow equations. This review then addresses the time compression approximation developed to estimate infiltration at the transition between preponding and postponding conditions. Finally, the effects of special conditions, such as the presence of air and heterogeneity in soil properties, on infiltration are considered.

show abstract

Section: Numerical Solutions Of the Infiltration Equationmentioning

confidence: 99%

Infiltration into soils: Conceptual approaches and solutions

Assouline

2013

Water Resources Research

208

115

View full text Add to dashboard Cite

show abstract

“…Since the objective function is just an algebraic function, which can be easily evaluated, the CPU time needed for the optimizations is trivial. The first inversion flow example uses numerically generated data by the same flow model described in section 2.2, assuming hydraulic parameters of Berino loamy fine sand as listed in Table 2 [Hills et al, 1989]. Advantages of using numerically generated data are that the true values of parameters are known and that no measurement or model errors exist, resulting in less uncertainty in the evaluations.…”

Section: Minimization Of An Objective Function With Multiple Local MImentioning

confidence: 99%

A hybrid global optimization method for inverse estimation of hydraulic parameters: Annealing‐Simplex Method

Pan¹,

Wu²

1998

Water Resources Research

View full text Add to dashboard Cite

Abstract. Inverse estimation of unsaturated hydraulic parameters is often a highly nonlinear optimization problem with multiple parameters. The objective functions involved are often topographically complex and may contain many local minima. Because of these reasons, the inverse solutions are commonly very sensitive to the initial guess of the parameters when conventional optimizers are used. This paper presents an annealingsimplex method that incorporates simulated annealing strategies into a classical downhill simplex method. An upward infiltration experiment was used as an example of inverse estimation to test the method. Numerical experiments of both minimizing an algebraic function and inversion of upward infiltration data showed that the new method successfully converged to the global minimum in all cases, irrespective of the initial hydraulic parameter estimates, while the classical downhill method often converged to unfavorable local minima. The CPU times needed for the annealing-simplex method to estimate 5 and 7 hydraulic parameters simultaneously are about a half hour and 1 hour on a PC, respectively. Additionally, no special requirements are imposed on the objective function, and the method is independent of the details of the simulation submodel. Therefore the proposed method should be applicable to other optimization problems in water resources when it is important to have a robust global search capability. IntroductionKnowledge of unsaturated soil hydraulic properties is essential for prediction of water flow and contaminant transport through the vadose zone. Specifically, the hydraulic properties are the water retention and hydraulic conductivity functions, both of which are highly nonlinear functions of the soil water pressure head. As opposed to more classical direct method, inverse estimation of the hydraulic properties from transient flow experiments has recently become more popular because of its flexibility in considering various data types, availability of more powerful computers, and the presence of increasingly accurate flow simulators [Kool and Parker, 1988 Hence, like many other geophysical inverse problems, the inverse estimation of hydraulic parameters of soils is a strongly nonlinear and multiparameter optimization problem that often involves finding the global minimum in between many local minima. The simulated annealing method, first incorporated into numerical calculations by Metropolis et al. The objective of this paper is to develop an effective and efficient inverse parameter estimator that can be used to find unique and stable parameter estimation given that the experiment is well designed to ensure identifiability. We will apply the estimation to the upward infiltration experiment described by Hudson et al. [1996]. A key step in our work is the development of a new technique of combining the classical downhill simplex method with the simulated annealing method in order to find the global minimum of the objective function in an efficient and effective manner. Being different ...

show abstract

“…The error is large when recharge or subsurface runoff is high. The water content formulation itself has been previously shown to cause solution instability for soils near saturation (Hills et al, 1989). Instead of solving the soil water and groundwater separately, we use a flow model for variably saturated porous media, STOMP (Subsurface Transport Over Multiple Phases) (White and Oostrom, 2000), to see if it can resolve the oscillation in the total soil C.…”

Section: Resultsmentioning

confidence: 99%

Accelerating the spin-up of the coupled carbon and nitrogen cycle model in CLM4

2015

View full text Add to dashboard Cite

Abstract. The commonly adopted biogeochemistry spin-up process in an Earth system model (ESM) is to run the model for hundreds to thousands of years subject to periodic atmospheric forcing to reach dynamic steady state of the carbonnitrogen (CN) models. A variety of approaches have been proposed to reduce the computation time of the spin-up process. Significant improvement in computational efficiency has been made recently. However, a long simulation time is still required to reach the common convergence criteria of the coupled carbon-nitrogen model. A gradient projection method was proposed and used to further reduce the computation time after examining the trend of the dominant carbon pools. The Community Land Model version 4 (CLM4) with a carbon and nitrogen component was used in this study. From point-scale simulations, we found that the method can reduce the computation time by 20-69 % compared to one of the fastest approaches in the literature. We also found that the cyclic stability of total carbon for some cases differs from that of the periodic atmospheric forcing, and some cases even showed instability. Close examination showed that one case has a carbon periodicity much longer than that of the atmospheric forcing due to the annual fire disturbance that is longer than half a year. The rest was caused by the instability of water table calculation in the hydrology model of CLM4. The instability issue is resolved after we replaced the hydrology scheme in CLM4 with a flow model for variably saturated porous media.

show abstract

Modeling one‐dimensional infiltration into very dry soils: 1. Model development and evaluation

Cited by 184 publications

References 16 publications

Infiltration into soils: Conceptual approaches and solutions

Infiltration into soils: Conceptual approaches and solutions

A hybrid global optimization method for inverse estimation of hydraulic parameters: Annealing‐Simplex Method

Accelerating the spin-up of the coupled carbon and nitrogen cycle model in CLM4

Contact Info

Product

Resources

About