Multifractal Characteristics of Soil Particle Size Distribution under Sewage Irrigation in Different Irrigation Years

Abstract

Soil particle size distribution (PSD) is one of the most important physical properties of soil due to its strong influence on hydraulic characteristic, fertility condition and erosion of soil, etc. Sewage irrigation causes the differences in soil PSD. Thus, there may be massive organic contaminants and suspended particles in soil. In this paper, the frequency and multifractal necessity of soil PSD under sewage irrigation in different years were analyzed. Soil PSD demonstrates a heterogeneous characteristic under sewage irrigation, and this heterogeneity can be characterized using the multifractal technique, which calculates the multifractal spectrum parameters. The results showed that the width of multifractal spectrum ∆α is directly proportional to clay content; a remarkable effect of sewage irrigation on multifractal parameters was observed. The soil structure quality decreased with increasing sewage irrigation years. However, the soil structure improved when the soil was irrigated with freshwater for a long period after sewage irrigation. Therefore, multifractal parameters may be potential indicators for the physical property and quality of soil.