A Hand-Portable Single Nozzle Rainfall Simulator Designed for Use on Steep Slopes

Abstract

The objective of this study was to develop a small plot (1 m2) rainfall simulator operational on steep terrain in the Guadalupe Mountains of New Mexico. The simulator developed is hand-portable and consists of a spray head assembly mounted on 3 adjustable legs. A 946-liter tank equipped with a gasoline powered pump was connected to the spray head assembly via rubber garden hoses. On steep slopes gravity provided sufficient pressure to operate the simulator. Site selection was limited to areas where the water tank could be located in a suitable upslope position. The simulator has been used for 2 years on 170 plots and has proved durable. Advantages of this device are the low cost of construction and operation, and the flexibility in plot-site selection it provides. The principal disadvantages are associated with the single stationary nozzle, such as uneven application of water at small drop sizes and low kinetic energies.