Study on Spatial Variability of Infiltration Characteristics in Yangling District
杨凌区土壤入渗特性的空间变异特征研究

Based on 44 groups of soil infiltration experiments in Yangling district, this paper analyzed the scaling process of Philip equation and disclosed the spatial variability of infiltration characteristics in Yangling district by using scaled theory, traditional statistical and geostatistics method. The results showed that the scaling of infiltration process based on aA was best among different scaling factors. The variable coefficient Cv of scaling factor aA was 0.257 5 which was medium variability, and aA was showed to be logarithmic normal distribution. Scaling factor aA was a second-order trend, and the best theoretical model of spatial variability of aA was spherical model, the proportion between nugget and sill was 0.228 0, showing aA had anisotropy and strong spatial correlation, and structural factors mainly caused the spatial variability of scaling factor aA. The results of ordinary Kriging interpolation showed that aA and the spatial distribution characteristics of accumulative infiltration in 90 min highly agreed with each other. The predicted values of aA of the 44 groups and accumulative infiltration in 30 min, 60 min, 90 min are compared with the measured values, and the mean absolute errors were 12.25%, 28.15%, 25.56% and 24.57%, respectively. Taking the actual situation into consideration, the predicted values in method of this paper is totally acceptable.