Approximate Explicit Solution to the Green-Ampt Infiltration Model for Estimating Wetting Front Depth

Abstract

Obtaining reliable information on the wetting front depth of soil is beneficial to the understanding of one-dimensional (1D) vertical infiltration under border irrigation. This paper presents an approximate explicit solution to the Green-Ampt (GA) infiltration model for estimating the wetting front depth. Moreover, the model proposed in this study, the GA model, the Ali model, and the Stone model were validated and evaluated using laboratory experimental data and HYDRUS-1D simulation. Statistical comparisons (root mean square error-RMSE, mean absolute percent relative error-MAPRE, and percent bias-PB) of the estimated data with the measured and simulated data were conducted. The models were ranked on the basis of their overall performance index (OPI). The results demonstrated that all four models can be used to estimate the wetting front depth of 1D vertical infiltration for a wide range of soil textures; the proposed model provided the most accurate result. According to comparisons of the estimated values with the measured and simulated values, the maximum RMSE, MAPRE, and PB were 1.74 cm, 6.92%, and −6.74%, respectively, for the proposed model. On the basis of the OPI, the optimal model was the proposed model, followed by the Ali, GA, and Stone models.

Fuzzy Analytical Solution to Vertical Infiltration

“…F z t is positive for every value of η, ξ and subsequently for all values of x and t. In order to examine the positivity of ( ) 3 , F z t , for a large spectrum of real soils, we examined 9 soils, whose properties are shown in Table 1. Soils 1 to 6 were taken from Nie et al [57], while soils 7 to 9 were taken respectively from Evangelides [58], Sakellariou-Makrantonaki [59] and Sismanis [60]. The diffusion coefficients D were calculated from the Van Genuchten formula [56]:…”

Numerical investigation of the performance of engineered barriers in controlling stormwater runoff

“…of the original model. [11][12][13][14][15][16] On the other hand, the Richards model combines the continuity equation (conservation of volume) with Darcy's law and leads to a partial differential equation (PDE) that describes flow in unsaturated porous media. Appropriate boundary conditions can be utilised for the modelling of rainfall precipitation and infiltration.…”

Numerical Investigation on Infiltration and Runoff in Unsaturated Soils with Unsteady Rainfall Intensity

“…Chu and Mariño [9] proposed an improved Green-Ampt model to simulate infiltration into layered soils, with arbitrary initial water content distributions subject to unsteady rainfall. Recently, the improvements of the Green-Ampt model make it applicable to a wider range of infiltration fields, and have achieved satisfactory results [10][11][12][13][14][15][16]. However, due to high sensitivity of the Green-Ampt model to the saturated hydraulic conductivity and the pressure head of wetting front, a comprehensive testing of this model is needed in order to calibrate its validity.…”