Simulation of Soil Moisture Characteristic Curve in the Typical Region of Hani Terraces

Taking Quanfuzhuang watershed of the Hani Terraces as the research object, the soil water characteristic curves of 0–10, 10–20, 20–40, 40–60, 60–80 cm and 80–100 cm deep layers were measured by pressure membrane method. Furthermore the Van–Genuchten model, the Brooks and Corey model and the Gardner model were selected to fit the curve and analyze the applicability of terraced soil data. The results show that under the same soil water suction, the soil water holding capacity in 0–10 cm and 40–60 cm layers was the worst, while the soil water holding capacity in 20–40 cm layers was the strongest. The Van–Genuchten, Brooks–Corey and Gardner models had similar trends with the measured values. They all had good fitting effects on 0–10 cm and 20–40 cm soil layers, but had poor simulation effects on 40–60 cm and 80–100 cm soil layers. The 3 models can be used to fit the soil water characteristic curve of Hani terraced field. The Van–Genuchten model has the best fitting effect with relatively small error, while Brooks–Corey and Gardner model have poor fitting effect. The Van–Genuchten model is an ideal fitting model for soil water characteristic curve of the Hani Terracs.