Evaluation of Infiltration Models and Variability of Soil Infiltration Properties at Multiple Scales

Soil infiltration is characterized by scale dependence, so the accuracy and reliability of indirect methods used to estimate soil infiltration properties from available soil physical data are often below expectations. This study aimed to determine the scale-dependent relationship between soil infiltration and soil physical properties and to establish pedotransfer functions (PTFs) for estimating normalization factors (F-C). Field studies were conducted using double-ring infiltrometers in the first (sandy loam) and third (clay loam) terraces in Yangling District. Multiple scale variability and relationships were studied by multifractal and joint multifractal techniques. Results indicated that the Kostiakov-Lewis model best described the relationship between cumulative infiltration and time in the study areas, and that the normalization equation for predicting cumulative infiltration was accurate. Joint multifractal analysis showed that the variability of F-C in the first terrace was related largely to sand content, soil bulk density, and silt content. F-C in the third terrace depended on the contents of sand, silt, initial soil water, and clay at multiple scales. The PTFs that were established based on the results of joint multifractal analysis reliably estimated F-C values. Copyright (c) 2017 John Wiley & Sons, Ltd.