Study On Hydraulic Parameters And Soil Solute Transport In Jiufeng National Forestry Park

At present, a variety of soil solute transport problems such as salinity, nutrients, heavy metals and other contaminants became a hot and difficult study of soil water movement. JiuFeng National Forestry Park belongs to mountain and stony area of north China, in recent years, soil physical and chemical properties, nutrient status, influencing factors of soil erosion and vegetation configuration measures were studied in the area by many researchers, but fewer studies on soil solute transport in the area. In this paper, using the basic theories of soil water dynamics and solute transport and the soil of the study area as the experimental materials, combined with indoor simulation experiments to study the various parameters of soil water movement and in saturated-unsaturated two states of soil solute breakthrough curves and its influence factors, aimed to provide reliable scientific basis of soil water and reasonable use of water resource protection in mountain and stony area of north China.Results were as follows:1. The centrifuge method was used for determination of soil water content and its corresponding water suction, using Gardner model, Brooks-Corey model and van-Genuchten model to fit the soil water characteristic curves, based on the experimental soil samples measurement and fitting data comparison, three kinds of models can reflect the relationship of the soil volumetric water content and soil water suction, but the van-Genuchten model fitted better.2. In the study area, soil water diffusivity and soil moisture content were positively related, consistent with the empirical formula, with the soil moisture increasing the different depths of soil water diffusivity increased but there were differences. The soil saturated hydraulic conductivity of each layers changed between0.47ml/min to5.18ml/min, mainly affected by the soil bulk density, clay content and porosity. The unsaturated soil hydraulic conductivity and soil water content were positively related, with the soil moisture increasing the different depths of soil hydraulic conductivity increased but there were differences.3. The infiltration of solute concentration had little effect on saturated soil solute breakthrough curves, were mainly affected by water pressures and soil structure; unsaturated soil solute breakthrough curves had solute preferential flow phenomenon, infiltration concentration and the water head pressures impact on the relative concentration of the leached solution small, mainly due to the soil structure characteristic and closely related to soil heterogeneity. Through the field dye tracing profiles of the study area, solute priority transport phenomena are through by macropore.