Experimental Research on Network Characteristics of Soil Non-uniform Flow

Preferential flow refers to such a flow transport pattern that water and solute flows round the soil matrixes, which contributes to accelerate the movement velocity in the soil, and soil recharge happens on the whole inlet boundary. Preferential flow is produced by a large number of macropores and fractures in the soil, such as root and wormhole, so it is of great importance to groundwater recharge due to its quick movement. For knowing the process of infiltration recharge, evaluating the recharge source underground water and analysis of subsurface water pollution, it's great significant to research the influence of preferential flow to soil moisture transport. In this study, according to the principle that iodine turns to blue after reacting with starch, outdoor tracer experiments of heterogeneous flow in clay loam are designed, from which the heterogeneous flow patterns are studied.