SPATIAL CHARACTERISTICS OF THE WATER MOVEMENT IN DIFFERENT SALINE ALKALI SOILS IN A TYPICAL COASTAL AREA

摘要

The spatial characteristics of soil water movement parameters form the basis and prerequisites for a complete understanding of the dynamic changes in soil moisture and are the most important hydraulic parameters for the simulation of soil water movement and solute transport. However, it is difficult to directly determine these parameters. Using data from many studies, this study analyzed and reviewed the unsaturated soil water movement parameters in a typical salinized area in Hebei Province. Soils with different salinization degrees (1.1, 2.6, 4.3, 7.5, and 14.2 g/kg, respectively) served as the research object, the vacuometer method was used to determine the soil-water characteristic curve of soil profiles, and the van Genuchten model in the RETC software program was used to fit the curves. The horizontal soil column method was employed to measure the soil water diffusivity, and power and exponential functions were selected for the curve fitting. The unsaturated hydraulic conductivity of a typical profile was indirectly calculated from the water capacity and diffusivity. The results show that the soil water suction increased with the decrease in the soil water content, while the soil water diffusivity increased with the increase in the water content. This study obtained parameters of soil water movement and analyzed their characteristics, which provides a theoretical basis for guiding local agricultural planting and improving saline-alkali land.