[1] The experimental evidence suggests that for many chemicals surface runoff and rapid preferential flow through the shallow unsaturated zone are significant pathways for transport to streams and groundwater. The signature of this is the episodic and pulsed leaching of these chemicals. The driver for this transport is the timing and magnitude of rainfall events which trigger rapid flow and the...

Preferential flow in the unsaturated soil is an important and common phenomenon, which is difficult to be characterized. The objective of this paper is to evaluate the Active Region Model (ARM), which incorporated the fractal flow patterns into the continuum approach, has been developed to characterize preferential water flow in the unsaturated zone. Experiments were conducted to measure water ...

Due to the long-term fluid-solid interactions in waterflooding, the tremendous variation of oil reservoir formation parameters will lead to the widespread evolution of preferential flow paths, thereby preventing the further enhancement of recovery efficiency because of unstable fingering and premature breakthrough. To improve oil recovery, the characterization of preferential flow paths is esse...

The fresh gas flow requirements of the Preferential Flow System have been compared with those of the Magill system in spontaneously breathing volunteers and found to be similar. A lower resistance to expiration was found with the Preferential Flow System and the effectiveness of the valveless method of flow direction was demonstrated.

Water scarcity constrains the livelihoods of millions of people in tropical drylands. Tree planting in these environments is generally discouraged due to the large water consumption by trees, but this view may neglect their potential positive impacts on water availability. The effect of trees on soil hydraulic properties linked to groundwater recharge is poorly understood. In this study, we per...

Preferential flow through soil macropores in tile drained soils can significantly increase the risk of pollution of surface water bodies by agricultural chemicals such as pesticides. While many field studies have shown the importance of preferential flow in tile-drained fields, few have included detailed numerical modelling of the processes involved. The objective of this study was to compare f...