A theoretical analysis of interflow of water through surface soil horizons with implications for movement of chemicals in field runoff

Ahuja, Lajpat R.; Ross, J. D.; Lehman, O. R.

doi:10.1029/wr017i001p00065

Cited by 22 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In an unsaturated soil, the ponding–runoff layer is not a fixed initial condition but a process that is dependent on rainfall and infiltration. Similar to the assumptions made by Ahuja et al (1981b) and Govindaraju et al (1996), chemicals in the soil mixing layer are the only sources of chemical constituents in infiltration and runoff water, and the chemicals are considered to transfer only vertically. The chemicals in the soil mixing zone could move into the underlying soil through the interface between them and the infiltrated water.…”

Section: Mathematical Model Developmentmentioning

confidence: 96%

Experimental study and mathematical modelling of soluble chemical transfer from unsaturated/saturated soil to surface runoff

Tong

Yang

et al. 2010

Hydrological Processes

View full text Add to dashboard Cite

Abstract:A one-dimensional, two-layer solute transport model is developed to simulate chemical transport process in an initially unsaturated soil with ponding water on the soil surface before surface runoff starts. The developed mathematical model is tested against a laboratory experiment. The infiltration and diffusion processes are mathematically lumped together and described by incomplete mixing parameters. Based on mass conservation and water balance equations, the model is developed to describe solute transport in a two-zone layer, a ponding runoff zone and a soil mixing zone. The two-zone layer is treated as one system to avoid describing the complicated chemical transport processes near the soil surface in the mixing zone. The proposed model was analytically solved, and the solutions agreed well with the experimental data. The developed experimental method and mathematical model were used to study the effect of the soil initial moisture saturation on chemical concentration in surface runoff. The study results indicated that, when the soil was initially saturated, chemical concentration in surface runoff was significantly (two orders of magnitude) higher than that with initially unsaturated soil, while the initial chemical concentrations at the two cases were of the same magnitude. The soil mixing depth for the initially unsaturated soil was much larger than that for the initially saturated soil, and the incomplete runoff mixing parameter was larger for the initially unsaturated soil. The higher the infiltration rate of the soil, the greater the infiltration-related incomplete mixing parameter. According to the quantitative analysis, the soil mixing depth was found to be sensitive for both initially unsaturated and saturated soils, and the incomplete runoff mixing parameter was sensitive for initially saturated soil but not for the initially unsaturated soil; the incomplete infiltration mixing parameter behaved just the opposite. Some suggestions are made for reducing chemical loss from runoff.

show abstract

Section: Mathematical Model Developmentmentioning

confidence: 96%

Experimental study and mathematical modelling of soluble chemical transfer from unsaturated/saturated soil to surface runoff

Tong

Yang

et al. 2010

Hydrological Processes

View full text Add to dashboard Cite

show abstract

“…Obviously the limits of these one‐dimensional simplifications are reached as soon as the soil is water saturated or the imposed water flux exceeds the saturated hydraulic conductivity. In both cases, the water content cannot be adjusted anymore and lateral water flux at the soil surface or at the surface of some impeding soil layer, also termed interflow (Ahuja et al, 1981), becomes dominant. Hence, we are back to a challenging three‐dimensional problem with additional structural heterogeneities to be considered including micro‐ and macrotopography of the soil surface and of impeding soil layers below ground as well as the horizontal connectivity of different soil types in the landscape.…”

Section: Scales and Scale Transitions Of Water Dynamicsmentioning

confidence: 99%

Scale Issues in Soil Hydrology

Vogel

2019

Vadose Zone Journal

View full text Add to dashboard Cite

Core Ideas The soil profile is the critical scale for representation of soil hydrology also at larger scales. Natural soils do not follow well‐defined hydraulic properties. Concepts are needed to model hydraulic nonequilibrium and hysteresis. Spatial patterns of functional soil types need to be identified. These can account for vertical stratification of hydraulic properties and structural attributes. Soil hydrology is a key control for the functioning of the terrestrial environment. Many environmental issues that we need to tackle today are directly linked to soil water dynamics. This includes agricultural production and food security, nutrient cycling and carbon storage, prevention of soil degradation and erosion, and last but not least, clean water resources and flood protection. However, these problems need to be addressed at the scales of fields, regions, and landscapes, while soil water dynamics and soil hydraulic properties are well understood and typically measured at much smaller scales—the comfort zone of soil physics. An obvious problem is how to link these vastly different scales and how to profit from small‐scale understanding to improve our capability to predict what is going on at the large scale. In this update, this problem is discussed based on insights gained during the last decades. As a synthesis, a two‐step scaling approach is proposed for modeling soil water dynamics from local to landscape scales where the scale of the soil profile is the stepping stone.

show abstract

“…The original presentation of the problem by KSW used unnecessarily complicated notation and included an unnecessary quadratic term. But KSW did provide a basis for later work, such as that by Ahuja [1981] and Ahuja and Ross [1982,1983].…”

Section: Discussionmentioning

confidence: 99%

“…The missing cash term is on the list. It is also apparent that Ahuja et al [1981] included the denominator cash.…”

Section: Introductionmentioning

confidence: 99%

Revisiting steady state water flow in a saturated, inclined soil slab

Prunty¹,

Padmanabhan²

1999

Water Resources Research

View full text Add to dashboard Cite

Abstract. Mathematical models of flow in a saturated, inclined soil slab with an impermeable lower boundary have contributed substantially to understanding of important processes in the environment. One such process is movement of chemicals induced by interflow in sloping soil. Certain aspects of previous mathematical treatment regarding the inclined soil slab problem have, however, escaped scrutiny. The original 1965 treatment includes a peculiar quadratic boundary condition term that applies over a vanishingly small fraction of the soil surface. The quadratic term is shown to be unjustified and unnecessary in obtaining practical solutions. Mathematical solutions of two more general inclined slab geometries, three-dimensional and parallelogram slabs, are presented and solved. The solutions are illustrated in terms of figures showing selected flow paths and equipotentials. IntroductionThe analysis of the problem of saturated, steady groundwater flow in an inclined soil slab by Klute et al. [1965] (henceforth KSW) led to better understanding of flow in sloping soil bodies. Their analysis provided all or part of the conceptual base for important later works. Citations recognizing the paper are numerous. However, the KSW approach uses a peculiar boundary condition at the soil surface which includes a quadratic term when the distance from the end of the slab is less than an arbitrary small value.Ahuja et al. [1981] extended the KSW approach to the cases of (1) sloping layered soil, (2) sloping soil with infinitely deep subsoil, and (3) sloping topsoil with constant flux into the subsoil. These theoretical results were subsequently corroborated with an experimental study [Ahuja, 1982]. Later works by Ahuja and Ross [1982, 1983] Considering the widespread citation of KSW, we believe that certain aspects need further discussion, clarification, and inspection. In addition, we will present solutions to two more general inclined slab problems. One is the problem of the three-dimensional inclined slab with its direction of maximum slope not aligning with either of the sides, and the second is the two-dimensional slab with vertical ends, in which the cross section of the slab is a parallelogram. The objectives of this paper are (1) to solve the saturated, two-dimensional inclined slab problem for a simplified formulation independent of KSW, (2) to compare the KSW solution to the independent solution, (3) to extend the inclined slab problem to the third dimension, and (4) to solve the inclined parallelogram slab problem.

show abstract

A theoretical analysis of interflow of water through surface soil horizons with implications for movement of chemicals in field runoff

Cited by 22 publications

References 15 publications

Experimental study and mathematical modelling of soluble chemical transfer from unsaturated/saturated soil to surface runoff

Experimental study and mathematical modelling of soluble chemical transfer from unsaturated/saturated soil to surface runoff

Scale Issues in Soil Hydrology

Revisiting steady state water flow in a saturated, inclined soil slab

Contact Info

Product

Resources

About