General Model for Unsaturated Hydraulic Conductivity for Soils with Lognormal Pore-Size Distribution

摘要: Describing water flow in unsaturated soils requires knowledge of the hydraulic conductivity. This study was conducted to develop a general conductivity model for with lognormal pore-size distribution based on Mualem-Dagan pore-scale model. The derived has three parameters other than retention model: α and β, both which are related soil pore tortuosity, parameter γ describe how evaluate effective radius. proposed applied observed data sets 200 soils. Results showed that β should be treated as fitted accurate descriptions conductivity, whereas estimation results were insensitive long optimized. Consequently, simplified form suggested uses constant value unity. Based model, two predictive methods (AB FN) developed. method AB values minimize average prediction error. FN an empirically relationship between dimensionless Both reduced error more 77% compared Burdine Mualem models. provided slightly better predictions AB, reducing by 28%.