Developing a novel method for estimating parameters of Kostiakov–Lewis infiltration equation

Alizadeh‐Dizaj

Ebrahimian

et al. 2022

Self Cite

The Kostiakov–Lewis equation is one of the commonly used infiltration equations in furrow irrigation. Elliott and Walker developed a two‐point method to estimate coefficients of the Kostiakov–Lewis equation. The basic infiltration rate (fo) in the Kostiakov–Lewis equation is usually calculated by the inflow–outflow method to determine the other two Kostiakov–Lewis parameters. In that method the entire furrow is used as an infiltrometer, which can cause overestimation of fo. In this study, by considering a correction factor in the mathematical calculations where the newly calculated value of fo is represented as fo* and the values of the a and k parameters, as calculated during the advance phase, are represented as a* and k*. The amount of infiltration volume estimated by the proposed method was evaluated using 21 open‐ended furrow irrigation data sets by calculating the relative error (RE) index. The value of fo decreased and the values of a and k increased by using the proposed method as compared to the Elliott and Walker method. Therefore, the results showed that the proposed method estimated infiltration volume with greater accuracy (average absolute RE = 4.0%) as compared to the Elliott and Walker method (average absolute RE = 7.8%).

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Estimating Infiltration in Open‐ended Furrow Irrigation by Modifying Final Infiltration Rate

Alizadeh‐Dizaj

Ebrahimian

et al. 2022

Self Cite

“…Due to soil texture variations along the field, the water advance equation is likely to be non‐exponential (Seyedzadeh et al ., 2020). Therefore, to calculate the average advance time along the field, the integral form of Equation is as follows:

\overset{t_{0 - x}}{false} = \frac{\sum_{i = 1}^{N} \overset{t_{i}}{false} normalΔ x_{i}}{x_{N}} \to ({,, \begin{matrix} x_{0}, t_{0} = 0 \\ \overset{t_{i}}{false} = \frac{t_{i} + t_{i - 1}}{2} \\ normalΔ x_{i} = x_{i} - x_{i - 1} \end{matrix})

where N is the total number of stations, i is the counter,Δ x i is the distance between the i th and i th − 1 stations (m),

\overset{t_{i}}{true}

is the average advance time between the i th and i th − 1 stations (min), and x 0 and t 0 are the location (m) and time (min) at the upstream end of the field, respectively.…”

Section: Proposed Methodsmentioning

confidence: 99%

“…Accurate prediction of the advance curve is less important than estimating the depth of water infiltration. Furthermore, in the above method, there is no correlation between the advance times of the two points, and the midpoint data are completely random (Seyedzadeh et al ., 2020). In this study, based on average advance time and average infiltration opportunity time, a different point will be introduced instead of the midpoint in the two‐point method.…”

Section: Introductionmentioning

confidence: 99%

Investigating the midpoint of a two‐point method for predicting advance and infiltration in surface irrigation^*

Seyedzadeh

Maroufpoor

2021

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This study used the location of the average advance time (method 1) and the mean infiltration opportunity time (method 2) as the midpoint of the twopoint method for determining "power advance" and Kostiakov-Lewis infiltration parameters. Experiments were carried out in three border-irrigated fields. The results showed that calibration of the power advance equation obtained by the Elliot and Walker method had high accuracy, with an average relative error of 11.3% in the time to complete the advance phase. The root mean square deviation (d RMS ) index used by Elliot and Walker showed that method 1, with an average d RMS value of 15.7 min, has the lowest d RMS , which estimates the advance time with mean d RMS values of 5.1 and 1.8 min less than the proposed method 2 and the method of Elliot and Walker, respectively. Furthermore, using all methods, the Kostiakov-Lewis infiltration equation parameters were determined. In estimating infiltration depth, method 1 had the highest accuracy with a minimum relative error of 0%, a maximum relative error of 8.7%, and an average relative error of 3.8%. Based on both the d RMS index and the accuracy of the infiltration equation, method 1 had a higher accuracy. K E Y W O R D S average advance time, design, evaluation, infiltration opportunity, volume balance Résumé Cette étude a utilisé l'emplacement du temps moyen d'avance (méthode 1) et le temps moyen d'occasion d'infiltration (méthode 2) comme point médian de la méthode à deux points pour déterminer les paramètres d'infiltration "avance de puissance" et Kostiakov-Lewis. Des expériences ont été menées dans trois champs irrigués selon la méthode border irrigation. Les résultats ont montré que l'étalonnage de l'équation d'avance de puissance obtenue par la méthode Elliot et Walker avait une grande précision, avec une erreur relative moyenne de 11,3% dans le temps pour terminer la phase d'avance. L'indice d'écart quadratique moyen ine (d RMS ) utilisé par Elliot et Walker a montré que la * Etude du point médian d'une méthode en deux points pour prédire l'avance et l'infiltration dans l'irrigation de surface

“…Therefore, due to the importance of the rate of water advance over a field, many researchers (Panahi et al, 2021; Seyedzadeh et al, 2019; Seyedzadeh, Panahi, Maroufpoor, Singh, et al, 2020) have developed various mathematical models to estimate soil physical properties, including infiltration and hydraulic roughness coefficients based on the rate of water advance along a field. Most of the models reported in the technical literature are based on a volume‐balance approach.…”

Section: Introductionmentioning

confidence: 99%

Subsurface shape factor for surface irrigation hydraulics

Seyedzadeh

Maroufpoor

et al. 2022

Self Cite

An improved analytic solution is presented to estimate soil water infiltration by surface irrigation methods through a more rigorous determination of the subsurface shape factor, as applied in volume‐balance models. Based on the results of this analysis and by averaging the shape factor of previously published equations, a new relationship is presented, with a maximum error of 0.036%. Also, the effect of these relationships on the empirical parameters for the Kostiakov–Lewis equation and the water infiltration depth were evaluated. Based on this evaluation, the relative error difference of the infiltration depth of the actual subsurface shape factor value and the new relationship was less than 0.01%. Given the high accuracy of the proposed methodology and the simplicity of its form, this relationship is recommended for use in practical work to predict surface irrigation hydraulic performance and irrigation application efficiency.