Research on Infiltration Rate of Topsoil in Combination with Steady Infiltration Model and Penetration Resistance Test

Abstract

In this study, infiltration experiment and survey on specific penetration resistance for the topsoil were conducted for five land use patterns at the Liudaogou Catchment on the northern Loess Plateau. A simple infiltration model has been developed based on water balance principle combined with theory of steady infiltration. The mean unsaturated infiltration rate of topsoil was estimated based on the results of infiltration experiment and survey on specific penetration resistance combined with model calculation. The results indicated that determination coefficient of relation curve between mean unsaturated infiltration rate and the topsoil specific penetration resistance is higher than 0.93; order of the mean unsaturated infiltration rate of topsoil was 10-5 m/s during the research period; sequence of the mean unsaturated infiltration rate of the five land use patterns is Alfalfa (on slope land) < Grassland (on slope land) < Grassland (on alluvial plain) < Farmland (on alluvial plain) < Sandy loess (bare land); mean unsaturated infiltration rate of alfalfa (on slope land) and grassland (on slope land) was obviously lower than that of the mean of the five land use patterns, and mean unsaturated infiltration rate of sandy loess (bare land) was significantly higher than that of the mean of the five land use patterns.