Effective Saturated Hydraulic Conductivity for Representing Field-Scale Infiltration and Surface Soil Moisture in Heterogeneous Unsaturated Soils Subjected to Rainfall Events

Ojha, Richa; Corradini, Corrado; Morbidelli, Renato; Govindaraju, Rao S.

doi:10.3390/w9020134

Cited by 11 publications

(16 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Not only was there nonuniqueness (equifinality) when dealing with data from a single rainfall‐runoff experiment, but also the posterior distributions of acceptable parameter combinations varied between experiments adding another layer of uncertainty. This outcome is in line with Ojha et al () and Langhans et al (), both of which concluded that the effective K s for a study area is dependent on rainfall. With natural field variability in soil hydrologic properties, there will likely be some portions of the field where the water supply is limiting and others where soil properties are limiting infiltration, and this control is expected to change as the storm progresses in time.…”

Section: Discussionsupporting

confidence: 91%

Estimation of Field‐Scale Variability in Soil Saturated Hydraulic Conductivity From Rainfall‐Runoff experiments

Goyal

Morbidelli

Flammini

et al. 2019

Water Resources Research

Self Cite

View full text Add to dashboard Cite

Saturated hydraulic conductivity (Ks) is among the important soil properties that influence the partitioning of rainfall into surface and subsurface waters. Point estimates of Ks are difficult to determine and exhibit large spatial variability in fields. Often, data from field‐scale rainfall‐runoff experiments are utilized to assess the properties of the Ks random field that are required in the use of field‐scale infiltration models. Standard methods of calibration are confounded by nonuniqueness and identifiability problems associated with experimental data. In this study, a new method that employed a field‐averaged infiltration model and Monte Carlo simulations was used to obtain the possible range of distributions of Ks that would describe experimental observations over a field for a rainfall event. A Shannon information‐theoretic approach was subsequently adopted to consolidate the ranges of Ks distributions over multiple rainfall events to yield the best range of Ks distributions. The method was applied to data from several rainfall‐runoff events observed under natural conditions over an experimental field characterized by a silty loam soil and a small surface slope. Results suggest the existence of numerous parameter combinations that could satisfy the experimental observations over a single rainfall event, and high variability of these combinations among different events, thereby providing insights regarding the identifiable space of Ks distributions from individual rainfall experiments. Validation results showed that the method provides a realistic estimate of our ability to quantify the spatial variability of Ks in natural fields from rainfall‐runoff experiments.

show abstract

Section: Discussionsupporting

confidence: 91%

Estimation of Field‐Scale Variability in Soil Saturated Hydraulic Conductivity From Rainfall‐Runoff experiments

Goyal

Morbidelli

Flammini

et al. 2019

Water Resources Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…Soil moisture is a variable that integrates the water balance components of land surface hydrology (Porporato et al, 2002), and over time it can be used to develop a record of antecedent hydrologic fluxes (Costa-Cabral et al, 2008). Soil moisture measurements were used to estimate the infiltration for unsaturated porous mediums by numerical solutions as early as the 1950s (Hanks and Bowers, 1962;Gardner and Mayhugh, 1958).…”

Section: Introductionmentioning

confidence: 99%

Quantification of soil water balance components based on continuous soil moisture measurement and the Richards equation in an irrigated agricultural field of a desert oasis

Li¹,

Liu²,

Zhao³

et al. 2019

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. An accurate assessment of soil water balance components (SWBCs) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information on SWBCs is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and can thus be used to determine SWBCs from a hydrologic balance. A database of soil moisture measurements from six experimental plots with different treatments in the middle Heihe River basin of China was used to test the potential of a such a database for estimating SWBCs. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (Ks) and soil water retention features, for supporting SWBC estimations. We then determined evapotranspiration and other SWBCs using a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well and published SWBCs values at nearby sites) and the water balance equation technique to verify the estimated SWBCs values, all of which showed good reliability with respect to our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the SWBC estimation and any restrictions regarding its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1–867.3 mm) and deep drainages (170.7–364.7 mm). Moreover, the un-mulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all of the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season due to the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the SWBCs in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.

show abstract

“…With the advantages of having a reasonable physical mechanism and easy-to-solve quantitative expressions, the GA model has been widely used in water infiltration calculations for a number of hydrologic scenarios, including homogeneous soil [10], inhomogeneous soil [11][12][13][14][15], ponding sites [16], non-ponding sites [17][18][19][20], steady rainfall, and unsteady rainfall [21,22]. In addition, several methods have been proposed for determining key parameters of the GA model [23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Feasibility Investigation of Improving the Modified Green–Ampt Model for Treatment of Horizontal Infiltration in Soil

Cao

Shi

Zhu

et al. 2019

Water

View full text Add to dashboard Cite

Water infiltration in soil is a complex process that still requires appreciation of interactions among three phases (soil particles, water and air) to enable accurate estimation of water transport rates. To simulate this process, the Green–Ampt (GA) model and the Modified Green-Ampt (MGA) model introduced in the paper “A new method to estimate soil water infiltration based on a modified Green–Ampt model” have been widely used. The GA model is based on the hypothesis that the advance of the wetting front in soil under matric suction can be treated as a rectangular piston flow that is instantaneously transformed after passage of the infiltration front, and the MGA model does not contain the influence of pore size change. This cannot accurately reflect the soil moisture change process from unsaturation to saturation. Due to soil stratification and other inhomogeneity, predictions produced with these models often differ widely from observations. To quickly obtain the soil moisture distribution after passage of the wetting front for horizontal infiltration, an improved modified Green–Ampt (IMGA) model is presented, which estimates the soil moisture profile along a horizontal column in a piecewise manner with three functions. A logarithmic function is used to describe the gradual soil saturation process in the transmission zone, and two linear functions are used to represent the wetting zone. The algorithm of the IMGA model for estimating the water infiltration rate and cumulative infiltration is configured. To verify the effectiveness of IMGA model, a lab model test was performed, and a numerical model was built to solve the horizontal one-dimensional Richards equation using the finite–element method. The results show that the IMGA model is more accurate than the GA and MGA models. The horizontal soil moisture profiles obtained by the IMGA model are closer to the measured data than the numerical simulation results. The relative errors of the MGA and IMGA models decrease with an increase in infiltration time, whereas that of the GA model first decreases and then increases with infiltration time. The primary novelty of this study is nonlinear description of soil moisture content distribution, and derivation of unit transfer coefficient.

show abstract

Effective Saturated Hydraulic Conductivity for Representing Field-Scale Infiltration and Surface Soil Moisture in Heterogeneous Unsaturated Soils Subjected to Rainfall Events

Cited by 11 publications

References 41 publications

Estimation of Field‐Scale Variability in Soil Saturated Hydraulic Conductivity From Rainfall‐Runoff experiments

Estimation of Field‐Scale Variability in Soil Saturated Hydraulic Conductivity From Rainfall‐Runoff experiments

Quantification of soil water balance components based on continuous soil moisture measurement and the Richards equation in an irrigated agricultural field of a desert oasis

Feasibility Investigation of Improving the Modified Green–Ampt Model for Treatment of Horizontal Infiltration in Soil

Contact Info

Product

Resources

About