Through a simulation test carried out with soil columns (61.8cm in diameter),the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensioneters.The results show that in the profile of whole silty loam soil,the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water;and in the profile with an intercalated bed of clay or with a thick upper layer of clay,the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil.In case of soil water being supplemented by precipitation,the evaporation of groundwater in the soil columns reduced,resulting in a great decline of salt accumulation from soil profile to surface soil.The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer.The direct infiltration depth of precipitation was less than 1m in general,but water pressure transfer could go up to groundwater surface directly.
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