A MODIFIED RAINFALL SIMULATOR: DESIGN PRINCIPLES, RAINFALL CHARACTERISTICS AND SIMULATION ABILITY TO NATURAL RAINS

The performance of rainfall simulators strongly depend on their construction properties and principles of operation. The most important criterion in evaluation of simulator performance is the compatibility of rainfall characteristics between simulated and natural rainfall. This study aims to (i) identify the simulator design principles (ii) determine the rainfall characteristics and (iii) measure the simulated rainfall’s representative ability of the natural rainfall in the region using a laboratory drop-former simulator with limited range of motion. As a result of this study, the physical and mechanical properties of the aforementioned rainfall simulator were clearly identified. It has been shown that the intensities of the eight different rainfalls varied between 18.8- 189.9 mm h-1, while their kinetic energy varied between 0.208-0.290 MJ ha-1 mm-1. The drop median values of the simulated rainfalls were between 2.26- 2.38 mm and the falling drop speed varied between 6.063-6.919 m sec-1. A logarithmic relationship (R2= 0.88) have been determined between the unit kinetic energies and the intensity values of the simulated rainfall. The results suggest that the rainfall simulator can successfully represent the natural rainfall and can be used effectively in soil erosion studies.