Pedosphere 12(4): 301--308, 2002
ISSN 1002-0160/CN 32-1315/P
©2002 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Applicability of fractal models in estimating soil water retention characteristics from particle-size distribution data |
| LIU Jian-Li and XU Shao-Hui |
| Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) |
| ABSTRACT |
| Soil water retention characteristics are the key information required in hydrological modeling. Fractal models provide a practical alternative for indirectly estimating soil water retention characteristics from particle-size distribution data. Predictive capabilities of three fractal models, i.e., Tyler-Wheatcraft model, Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental data from an international database and literature. Particle-size distribution data were firstly interpolated into 20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the pore surface were then calculated from the detailed particle-size distribution and incorporated as a parameter in fractal water retention models. Comparisons between measured and model-estimated water retention characteristics indicated that these three models were applicable to relatively different soil textures and pressure head ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- and medium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of water contents at low pressure heads than at high pressure heads. |
| Key Words: fractal model, particle-size distribution, soil water retention characteristics |
| Citation: Liu, J. L. and Xu, S. H. 2002. Applicability of fractal models in estimating soil water retention characteristics from particle-size distribution data. Pedosphere. 12(4): 301-308. |
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