Evaluation of a general model for multimodal unsaturated soil hydraulic properties

Title:

Evaluation of a general model for multimodal unsaturated soil hydraulic properties

Creator:

Seki, Katsutoshi, Toride, Nobuo, and van Genuchten, Martinus Th.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:bddb7572-948b-40c8-b8b4-011579db36d0
uuid:bddb7572-948b-40c8-b8b4-011579db36d0
doi:10.2478/johh-2022-0039

Subject:

water retention, unsaturated hydraulic conductivity, general hydraulic conductivity model, and multimodal hydraulic models

Type:

model:article and TEXT

Format:

počítač and online zdroj

Description:

Many soils and other porous media exhibit dual- or multi-porosity type features. In a previous study (Seki et al., 2022) we presented multimodal water retention and closed-form hydraulic conductivity equations for such media. The objective of this study is to show that the proposed equations are practically useful. Specifically, dual-BC (Brooks and Corey)-CH (common head) (DBC), dual-VG (van Genuchten)-CH (DVC), and KO (Kosugi)1BC2-CH (KBC) models were evaluated for a broad range of soil types. The three models showed good agreement with measured water retention and hydraulic conductivity data over a wide range of pressure heads. Results were obtained by first optimizing water retention parameters and then optimizing the saturated hydraulic conductivity (Ks) and two parameters (p, q) or (p, r) in the general hydraulic conductivity equation. Although conventionally the tortuosity factor p is optimized and (q, r) fixed, sensitivity analyses showed that optimization of two parameters (p + r, qr) is required for the multimodal models. For 20 soils from the UNSODA database, the average R2 for log (hydraulic conductivity) was highest (0.985) for the KBC model with r = 1 and optimization of (Ks, p, q). This result was almost equivalent (0.973) to the DVC model with q = 1 and optimization of (Ks, p, r); both were higher than R2 for the widely used Peters model (0.956) when optimizing (Ks, p, a, ω). The proposed equations are useful for practical applications while mathematically being simple and consistent.

Language:

Slovak

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

22-34

Source:

Journal of hydrology and hydromechanics | 2023 Volume:71 | Number:1

Harvested from:

CDK

Metadata only:

false