Analysis of the Influence of Data Obtained at Low Suctions on Soil Water Retention Curve
Abstract：In this study, soil water contents of three soil horizons (0-10 cm, 10-20 cm and 20-30 cm) on a sloping farmland were measured by sand box method and pressure chamber method. The van Genuchten model (1980) was fitted to soil water retention data using RETC. The results showed that soil volumetric water content in the low suction range changed dramatically with the increase of suction, while chan- ging slowly in the high suction range. The shapes of SWRC were similar for different soil horizons. The obvious "S" shape of SWRC obtained from data measured using both a sand box and a pressure chamber was not observed when the data were obtained using only a pressure chamber. The fitted value of soil reidual water content (θr) was dose to the soil water content measured at a suction of 15 000 cm only when data at low suctions were included.
Keywords：soil water retention curve pressure chamber sand box van Genuchten model parameter
Publication Date：2012-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：4( 56-59 )