RESEARCH ON WATER MOVEMENT PARAMETERS OF INFERIOR SOIL OF DIFFERENT SITE TYPES IN MINING AREAS

The present research aims to explore the difference in water movement parameters of inferior soils in different site types; the undisturbed soil, mine-accumulated soil and ecologically modified soil in Wujiata Mining Area, Yiqi, Erdos City, Inner Mongolia, were taken as the research objects. The soil texture, soil diffusivity and water characteristic curve were measured through laboratory tests, and the soil water characteristic curve model suitable for inferior soils in mining areas was selected, and the variation laws of soil hydrodynamic characteristics such as water retention characteristics, effective water content and water conductivity characteristics of inferior soils in different site types were discussed. The Van Genuchten (VG) model shows the best fitting effect on the soil water characteristic curve model of inferior soils of different site types in mining areas. Under the same pressure head, the water characteristic curves of different horizons of soil are quite different; under the condition of 0-7000 cm pressure head, the water-holding capacity of undisturbed soil, mine-accumulated soil and ecologically modified soil decreases with the increase of depth. The soil water characteristic curve changes greatly in the low-pressure head section (<1000 cm) and relatively gently in the middle and high-pressure head section (>1000 cm). The water-holding capacity of ecologically modified soil is obviously enhanced. Ecological restoration can improve the poor soil structure in the research area, optimize the soil structure, and control the soil erosion obviously.