title: A user-friendly modified pore-solid fractal model.
abstract: The primary objective of this study was to evaluate a range of calculation points on water retention curves (WRC) instead of the singularity point at air-entry suction in the pore-solid fractal (PSF) model, which additionally considered the hysteresis effect based on the PSF theory. The modified pore-solid fractal (M-PSF) model was tested using 26 soil samples from Yangling on the Loess Plateau in China and 54 soil samples from the Unsaturated Soil Hydraulic Database. The derivation results showed that the M-PSF model is user-friendly and flexible for a wide range of calculation point options. This model theoretically describes the primary differences between the soil moisture desorption and the adsorption processes by the fractal dimensions. The M-PSF model demonstrated good performance particularly at the calculation points corresponding to the suctions from 100 cm to 1000 cm. Furthermore, the M-PSF model, used the fractal dimension of the particle size distribution, exhibited an accepted performance of WRC predictions for different textured soils when the suction values were ≥100 cm. To fully understand the function of hysteresis in the PSF theory, the role of allowable and accessible pores must be examined.
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.|College of Water Resources and Architecture Engineering, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.|School of hydraulic energy and power engineering, Yangzhou University, Yangzhou 225127, P. R. China.
authors.forename: Dian-Yuan
authors.initials: DY
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.|Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.|College of Water Resources and Architecture Engineering, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
authors.affiliation: College of Water Resources and Architecture Engineering, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.
authors.forename: Bing-Cheng
authors.initials: BC
authors.lastname: Si
authors.affiliation: Department of Environmental Science and Technology, University of Maryland, College Park, MD 20742, USA.
authors.forename: Robert Lee
authors.initials: RL
authors.lastname: Hill