Experimental Investigations on Influence of Fracture Networks on Overland Flow and Water Infiltration in Soil

Abstract

Soil preferential flow is an essential process that affects the movement and relocation of soil water and solutes. This study was conducted on cropland in an arid and semi-arid area in Zhongning County, Ningxia. According to the different cracks, rain intensity, rainfall duration, and slope, there were three groups, and 17 dye tracer experiments were conducted in the field. We quantified the characteristics of soil preferential flow by investigating and analyzing the infiltration depth, dyeing area, saturation, runoff coefficient, and rainfall infiltration coefficient using the dye tracer method. The results showed that increasing the rainfall or irrigation intensity could promote the activation of the fracture channel as the preferential flow channel, which is advantageous to the preferential flow formation. The fractures dominated the formation of the preferential flow. The fractures slowed the formation of runoff, reduced the velocity of slope flow, reduced the flow of the slope, and increased the amount of soil water infiltration. These results have theoretical and practical significance for understanding soil water transportation, especially for agricultural irrigation management and improving cropland water use efficiency in arid and semi-arid areas.

Study of the Soil Water Movement in Irrigated Agriculture Ⅱ

“…Modeling and flow simulation of soil water movement depend on an accurate description of the hydraulic properties and their measurements (in situ and in the laboratory). Obtaining infiltration equations that accurately estimate the amount of water infiltrating the soil always remains an open issue [5,6].…”

“…This Special Issue of Water contains seven papers covering many aspects of the abovementioned challenges [2][3][4][5][6][7][8], and a wide range of different regions and conditions.…”

“…You et al [5] examined the role and characteristics of preferential flow in understanding soil water transportation, especially in agricultural irrigation management and for improving cropland water use efficiency in arid and semi-arid areas. Seventeen dye tracer experiments were conducted in the field.…”