Development And Evaluation Of Pedo-transfer Functions Of Soil Moisture Characteristic Of Multi-scale In Korqin Sandy Land

In order to quickly and easily obtain accurate soil water characteristic curves, the typical dune-meadow areas in Horqin sandy land was selected as the study area. Established the pedo-transfer functions(PTFs) between the soil water characteristic curves (SWCC) and the soil basic properties such as bulk density、soil particle size distribution、SOM、EC、pH by the nonlinear programming method and fractal dimension model. The main conclusions were as follows:1. Statistical the physical and chemical properties and hydraulic properties of the different landscape and different landuse under three sampling scale. It showed that the soil in the study were coarse and lower nutrient content. The mostly texture of the study area is sand, as well as small amount of sandy loam and loamy sand.2. Nonlinear optimal programming method, which was used to establish the pedo-transfer functions between soil properties and parameters of van Genuchten model under three different sampling scales. There were different regular of different sampling scales. In the large sampling scale, the measured value and predicted value has the highest extent consistent. When the sampling data are abundant, reasonable layout of sampling points, the soil water characteristic curve created by the pedo-transfer function can be applied to this area or the regional which has the similar soil.3. Soil which has the self-similarity or fractal feature. The fractal dimension of the particle size distribution was ranged 1.23 to 2.35, at a low level. The fractal dimension ascends in the order of sand dune, semi-fixed dune, fixed dune, farmland, meadow. The relationship between fractal dimension and content of sand, silt, clay is not simply the linear correlation, but showed a significant correlation between the logarithm.4. The fractal dimension of soil water characteristic curve model has a good linear relationship with soil particle distribution fractal dimension. Established equation has the consistency at different sampling scale.5. The statistical model of the different sampling scale is difference, while fractal model under different sampling scales showed consistency.