low-intensity, high-uniformity water application system

Rainfall simulators with high uniformity and low intensities are required in many research areas related to environmental quality. To examine the characteristics of field-scale macropore-type preferential flow, we designed a portable water application system suitable to apply water with intensity < 5 mm h(-1) for long-term steady-state infiltration experiments under different climatic conditions. Our results showed that, when water was applied at 345 kPa pressure, the system could deliver 4.36 mm h(-1) of water to 19.2 by 2.7 m with 80 to 85% uniformity, while uniformity of the inner 16.2 by 2.1 m reached 94 to 97%. The performance of this system was not influenced by the ambient wind speed. Lower intensities of water application can be achieved by applying water intermittently.