Simultaneous Inverse Estimation of Soil Hydraulic and Solute Transport Parameters From Transient Field Experiments: Homogeneous Soil

Abstract

ABSTRACT. Inverse estimation of unsaturated soil hydraulic and solute transport properties has thus far been limited mostly to analyses of one-dimensional experiments in the laboratoryshort distances (Biggar and Nielsen, 1976;Bresler et al., 1984), thus making it difficult to assign values that are applicable at the field scale.A wide range of models exists for simulating water flow and solute transport in the vadose zone. Addiscott and Wagenet (1985) gave a review of one-dimensional (1-D) transport models. They compared and classified the models as being deterministic or stochastic, mechanistic or functional, numerical or analytical, and research or management oriented. They also discussed the degree of complexity, flexibility, transferability, and usefulness of these models for field conditions. One-dimensional water flow and solute transport models (such as those developed by Jarvis et al., 1991;Sulekha and Duijnisveld, 1998;Shao et al., 1998;Simunek et al., 1998; among others) are useful for many applications. While requiring less expertise in programming, fewer input data, and less computer time and memory than two-dimensional (2-D) models, 1-D approaches generally do not accurately describe geometry and thus the dynamics of water and solutes during irrigation using furrows, drippers, perforated tubes, and porous lines, or some other method. In such cases, flow and transport are two-or even three-dimen-W

Different scenarios for inverse estimation of soil hydraulic parameters from double-ring infiltrometer data using HYDRUS-2D/3D

“…2), so by assuming θ r as a constant value (ie in scenarios 2, 6, and 10), the estimation of the parameters was improved (Table 1). This finding is in line with other studies stating that sensitivity to the pore-connectivity parameter (l) is the lowest (Abbasi et al, 2003). Among the Mualemvan Genuchten hydraulic parameters, as mentioned by Ritter et al (2004), θ s has a clear physical meaning and can be measured directly.…”

“…It is commonly reported that some additional information is needed to obtain unique solutions for a large number of parameters. Such additional information could include water contents and/or pressure heads (Šimůnek and van Genuchten, 1996), solute concentrations (Abbasi et al, 2003), or temperatures (Nakhaei and Šimůnek, 2014) measured at a certain depth in the soil profile. However, little is known about the effect of including additional data as a predictor on the efficiency and uniqueness of inverse modelling of double-ring infiltrometer data.…”

A review of model applications for structured soils: a) Water flow and tracer transport

“…Water contents, infiltration rates, and resident solute concentrations were used in the objective function. The similarity of the inverse 2D MIM and SPM results led to the conclusion that equilibrium transport prevailed at this field site (Abbasi et al, 2003). Regarding this conclusion one must caution that the spatial resolution of concentration data sampled at discrete positions is usually insufficient to detect PF (e.g., Kasteel et al, 2005).…”

“…Modified HYDRUS-2D model was used in several studies comparing 2D-approaches based on SPM, MIM, or DPM for simulating PNE tracer transport in agricultural fields (e.g., Abbasi et al, 2003Abbasi et al, , 2004Köhne and Gerke, 2005;Haws et al, 2005;Köhne et al, 2006b). Abbasi et al (2003) compared the 2D MIM and SPM using inverse simulations of water flow and tracer movement at a sandy loam field plot with furrows (3 m × 3 m) in Phoenix, Arizona.…”

“…Abbasi et al (2003) compared the 2D MIM and SPM using inverse simulations of water flow and tracer movement at a sandy loam field plot with furrows (3 m × 3 m) in Phoenix, Arizona. The topography of the furrow cross-sections was considered explicitly in the numerical grid.…”