Spatial variability of soil infiltration characteristics and its pedo-transfer functions

Based on the experimental data collected from the first terrace in Yangling station,we perform both multifractal analysis and joint multifractal analysis to investigate the spatial variability and relationship between the stable infiltration rate and soil infiltration characteristics,and establish the pedo-transfer functions(PTFs) of soil infiltration characteristics.The results show that the infiltration characteristics are multifractal.The observed spatial variability of stable infiltration rate and the beginning 30-min cumulative infiltration are mainly caused by the different sand and clay contents in the soil samples.The multi-scale analysis results show that the spatial variations of soil sand content and organic matter content have significant influences on the spatial variability of steady infiltration rates.The beginning 30-min cumulative infiltration is mainly affected by the distributions of slit and clay content which are the same factors in multi-scale as the observation scale.Two pedo-transfer functions of infiltration characteristics are established with the joint multifractal analysis and the beginning 30-min cumulative infiltration,respectively.The computational error of the former is less,the later is relatively larger.