Infiltration Conditions, The Temperature On Soil Water Movement And Parameters Affect The Experimental Study,

The paper is based on national and international research on the temperature effect on soil water movement and retention, combines with the require of mantle technique development, quantitatively analyzes temperature effect, preliminarily study the temperature effect mechanism.According experiment requirement, developing a set of constant temperature equipment, with a temperature fluctuant range of±0.5℃.At 5, 17, 29 and 40℃,horizontal, vertical and point infiltration experiments are compared respectively. Power function may be used to describe the relationships between the wetting front distant, cumulative depth of infiltration and temperature. With the temperature increasing, the average water content in wetting region decrease. Diffusivity is power function of temperature, and hydraulic conductivity is as well as. Soil water characteristic curves tend to decrease with increasing temperature, and temperature effect of soil matric potential decrease with increasing water content as the water content is less than saturated water content.One mechanism of temperature effect is that temperature influence water characters, such as surface tension and viscidity, the other one is that temperature affect on the quantity of air in experiment column.Put the soil water movement parameters into Richard's equations, and use finite difference method to resolve Richard's equations.The research results in the paper are beneficial to further study water and heat coupling effect, to exactly describe the soil water movement in the filed.