Pedo-transfer functions for estimating the hydraulic properties of paddy soils in subtropical central China

摘要

Pedo-transfer functions (PTFs) have been widely used to estimate soil hydraulic properties in the simulation of catchment eco-hydrological processes. However, the accuracy of existing PTFs is usually inadequate for use. To develop PTFs for local use, soil columns were collected from a double rice-cropped agricultural catchment in subtropical central China. The PTFs for saturated soil hydraulic conductivity (K-s) and parameters ((s), , and n) of the van Genuchten model for the soil water retention curve (SWRC) were obtained based on soil's basic properties, and compared with models developed by Li et al. in 2007 and Wosten et al. in 1999, respectively. Our results indicated that K-s in the range of 0.04-1087cmd(-1) and (s) in the range of 0.34-0.51cm(3)cm(-3) were both well estimated with the R-adj(2) of 0.72 and 0.87, respectively, but (0.04-0.65cm(-1)) and n (1.05-1.21) were relatively poorly predicted with the respective R-adj(2) of 0.38 and 0.55, despite the use of more input parameters. Our local derived PTFs outperformed the other two existing models. However, if the local PTFs for paddy soils are not available, the Wosten et al. 1999 model can be proposed as a useful alternative. Therefore, this study can improve our understanding of the development and application of PTFs for predicting paddy soil hydraulic properties in China.