Study on soil-water characteristics of L_5- S_8 in Luochuan,Shaanxi

On the base of the determination of the soil-water characteristic curves and field moisture capacity of undisturbed soil samples of L 5-S 8 in Luochuan,we analyzed the properties of moisture preserve,supply and storing and effective moisture content,and discussed preliminarily the different causes of soil-water characteristics of L 5-S 8.The results indicate that the soil-water characteristic curves of L 5-1-S 8-2 are in well accordance with Van Genuchten model and the values of R2are all above 0.98.The water-preserved properties of L 5-1-S 8-2 become weaker with the increase of suction value in 0 ~ 85KPa.The water-preserved properties of the L 5-1-L 8-2 are stonger than that of the S 5-1-S 8-2,and the water-preserved properties of the L 5-1-L 8-2 are weeker than that of the S 5-1-S 8-2.The properties of water supply of L 5-1-S 8-2 become weaker with the increase of suction value in 0 ~ 85KPa,and the properties of water supply of the L 5-1-L 8-2 are stonger than that of the S 5-1-S 8-2.The direct reason of properties differences of L 5-S 8 is the different pore size distribution and clay content etc,and the underlying reason is the cold-dry and warm-wet climate change in soil development process.