Numerical simulation of salt leaching for the saline-alkali soil with clay interlayer Ⅰ: Models establishment and validation

摘要

Salt-alkali-related soil degradation is a worldwide environmental problem that attracts researchers’ continuous attention for many years. In order to reclaim saline soil, slat leaching which is considered as the most direct method is always used. Models used to describe soil water and salt dynamics which are essential for establishing salt leaching theory are always absolutely necessary. In this paper, two-dimensional water flow and salt transport models were developed for researching salt transportation during leaching in a soil domain above a silo drilled throughout the clay subsoil. The corresponding boundary conditions were established and models were solved by finite difference method. Based on the experiment carried out in northwest China, the calibration and validation were realized and the result showed that the general trend of the simulated soil salt contents after leaching matched better with the observed values. The models could successfully simulate salt distribution of such leaching process and provided a reasonably good link for salt transportation research in saline-alkali soil.