Improved calculation of soil hydraulic conductivity with the simplified evaporation method

Author(s)

Inforsato, Leonardo ; Iden, Sascha ; Durner, Wolfgang ; Peters, Andre ; van Lier, Quirijn De Jong

• Document type: Journal article
• Source: VADOSE ZONE JOURNAL; v. 22, n. 5, p. 9-pg., 2023-07-25.

Abstract

Numerical modeling of soil water dynamics and storage is generally based on the Richards equation. Its solution requires knowledge of the soil hydraulic properties (SHP): the soil water retention function and the hydraulic conductivity function. To determine SHP, laboratory evaporation experiments are particularly popular because they provide data for both SHP functions. The evaluation by the simplified evaporation method (SEM) method, originally proposed by Schindler and subsequently improved by several authors, relies on linearization assumptions that allow for a relatively simple calculation scheme but result in biased conductivity data for some soils. The objective of this study is to propose and test an improved computational scheme for the hydraulic conductivity function. We present the new theory and show that it leads generally to higher accuracy of the conductivity function. The improvement is most pronounced for sandy soils and soil water pressure heads below -100 cm, where the original method provided data with bias. (AU)

• FAPESP's process: 18/20902-2 - Development and functional evaluation of laboratory methods to determine soil hydraulic properties and their relation to crop water availability
• Grantee: Quirijn de Jong van Lier
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/00145-2 - Development of methodology to obtain soil hydraulic properties assisted by evaporation experiment in laboratory
• Grantee: Leonardo Inforsato
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 21/10520-8 - Uncertainty assessment of soil hydraulic parameterization by inverse modelling of evaporation experiments
• Grantee: Leonardo Inforsato
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate