Characteristics of Sand Soil Water and Salt Movement under Brackish Water Infiltration with Different Mineralization Degrees

The changes of the cumulative irrigation amount and wetting front transport distance versus infiltration time were analyzed through infiltration experiments under brackish water irrigation with different mineralization degrees,as well as soil water content and electrical conductivity after infiltration.The results showed that:with the increase of cumulative irrigation amount,the wetting front distance in horizontal direction was greater than the wetting front distance in vertical direction during the early infiltration stage.Initial infiltration rate was larger,and the rate gradually decreased;After infiltration for 30min,the influences of mineralization degrees on wetting front distance were more obvious,and the higher the mineralization degree,the greater the wetting front distance and the shorter the time.There was a good power function between wetting front distance and infiltration time,as well as between the cumulative irrigation amount and infiltration time.Electrical conductivity and soil water content near soil surface were mainly influenced by water quality,and soil water content in wetting front changed heavily.