DESIGN AND CONSTRUCTION OF A SIMPLE RAINFALL SIMULATOR FROM LOCALLY AVAILABLE MATERIALS

Abstract

Rainfall simulator is an important instrument for producing artificial rainfall for the determination of soil loss from a catchment over a given period of time. The instrument is rarely available in most Nigeria Universities for practical demonstration for students and research in Soil and Water Conservation Engineering. This is due to high cost of the rainfall simulator and materials that are commonly used for the construction of rainfall simulator are not readily available or expensive in developing countries. In this study, a pressurized rainfall simulator was designed and constructed using the locally available materials mainly PVC pipe, shower rose and a pump for supplying water to the simulator for its operation. The main-pipe receives water from the pump and supplies it to the laterals. The laterals supply water to the distribution pipe which passes it to the shower rose. One hundred shower roses on ten laterals spray water to the ground surface through 2 mm openings. The simulator was 3 by 3 m and all the components are detachable for portability. The simulator rests on an adjustable frame which could be varied from 1 to 2 m height. The uniformity coefficient and drop velocity from the simulator during the performance test were 84.4 % and 8.156 m/s, respectively. The results of uniformity coefficient and drop velocity were within the range. The intensity of water dropping from the simulator depends on the inflow rate of water which could be regulated by the control tap fixed to the inlet main-pipe.