Numerical Simulation of Salt Transportation During Leaching Through Layered Saline Soil

摘要

Salt-related soil degradation is considered a major threat to sustainable agriculture under semi-arid conditions. It 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. In this paper, HYDRUS-2D was used for researching salt transportation during leaching in a soil domain above a silo drilled throughout the clay subsoil. Based on the experiment carried out in Shule River basin 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. HYDRUS-2D could successfully simulate salt distribution of such leaching process and provided a reasonably good link for salt transportation research in saline soil. The results of salt transportation characteristics during the leaching demonstrated that with same water quota of leaching and same radius of silo, different existence and depth of clay interlayer needed different time for salt leaching down the soil profile. Additional applies will be carried out to illustrate the models' capacity for application to a broad range of soils.