Water-vapour sorption isotherm and water retention characteristics model


University of Salford conducts:

  • The laboratory tests for the WR effects on soil water retention capacity
  • Characterization modelling for WR influence on soil hydrological properties

The water retention characteristic model adopted for the WATERAGRI project is developed based on the concept of interfacial physics. There are three different water phases co-exists in unsaturated soils, they are the bulk water in fully occupied pore space, the water vapor in the empty pore space and the water film on the empty pore walls. The model describes and assess the three phases in terms of their respective states using classic physical interfacial theory. It gives out an explicit mathematical expression for the state of the three phases, which establishes a state equation for the soil water retention characteristics at different water contents or pore water saturation, from fully dry to fully wet.

The water retention characteristic model provides the subsurface hydrology modeler an reliable and convenient tool and the end user accurate assessment for the water retainer effect on soil water retention capacity.

Developed by


Dr. Yu Wang


Case Study

Where We Test Our Solution

The hydrological Characterization model will be implemented in the decision platform for the assessment of the Water Retainer use.

Solution Test Progress

  • Water retention curve test

  • Water diffusion test


  • Evaluation of Water Retainer Effect on Soil Water Retention using a Simple Desorption Method (in progress)
  • A Research Study on Water Retainer Effect on Unsaturated Soil Water Retention Curve (in progress)
August - October 2022
August - October 2022

Water retainer effect on water retention curve test for three types of soils.

February - April, 2022
February - April, 2022

Water retainer effect on the water diffusivity - 1st phase.

November 2022 - February, 2023
November 2022 - February, 2023

Water retainer effect on the water diffusivity - 2nd phase.

March - September 2023
March - September 2023

Water retainer effect on water retention curve test for more types of soils.

September 2022 - September 2023
September 2022 - September 2023

Experimental data analysis and modelling.

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