Numerical Investigation on the Temperature Effect on the Transport of Soil Solute

In the present paper, a mathematical model called the TE-Model has been built to describe the simultaneous transport of heat, water, gas, and solute in soil, in which the temperature effects on the transports of soil water and soil solute were taken in account. When the temperature effect was neglected, we call it the NTE-Model. Taking NaCl as an example, numerical calculations under constant environmental factors have been carried out to investigate the temperature effect on the transport of soil solute, which showed that the concentrations of NaCl in deep soil layers rose rapidly at the initial stage and then the upward movements slowed down. However, there was a large hysteresis in the concentration variation of soil solute in the shallow layers. After the initial stage, the concentration of NaCl rose almost linearly with time. Furthermore, the concentrations calculated through the TE-Model was larger than those calculated through the NTE-Model. At the conclusion of the 5-year calculating process, relative deviations in soil solute concentration at 10 different depths have been found to reach 61.5%, 59.6%, 54.7%, 49.2%, 44.5%, 40.9%, 37.5%, 34.1%, 29.8%, and 23.0%, respectively. (C) 2006 Wiley Periodicals, Inc.