A model for thermal influence on water retention curve in high suction range

The thermal influence on water retention curve in the high suction range was investigated theoretically. According to the thermodynamics of sorption and the Le Chatelier's principle, water adsorption by soil was always an exothermic process, and it was an inevitable phenomenon that the water retention capacity in the high suction range reduced with increasing temperature. Assuming that the adsorption heat was independent on temperature and the water retention curves at different temperature were parallel, a model was established to describe the thermal influence on the water retention curve. Comparisons were made between the model predictions and the test results in literatures. Good agreements of those comparisons showed that the model had the capability to cover the full suction range.