Pedo-transfer functions for estimating the hydraulic properties of paddy soils in subtropical central China |
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Authors: | Ganghua Zou Yi Wang De Li Liu Xinliang Liu Yuyuan Li |
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Institution: | 1. Key Laboratory of Agro-ecological Processes in Subtropical Region and Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, P.R. China;2. The University of Chinese Academy of Sciences, Beijing, P.R. China;3. NSW Department of Industry, Skills and Regional Development, Wagga Wagga Agricultural Institute, Wagga Wagga, Australia |
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Abstract: | 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 (Ks) and parameters (θs, α, 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 Wösten et al. in 1999, respectively. Our results indicated that Ks in the range of 0.04–1087 cm d?1 and θs in the range of 0.34–0.51 cm3 cm?3 were both well estimated with the R2adj of 0.72 and 0.87, respectively, but α (0.04–0.65 cm?1) and n (1.05–1.21) were relatively poorly predicted with the respective R2adj 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 Wösten 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. |
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Keywords: | Soil physics water movement vadose zone parameter estimation |
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