COMPARISON OF GERMAN AND SWISS RAINFALL SIMULATORS - RELATIVE DROP ENERGIES AND THEIR DISTRIBUTION IN TIME AND SPACE FOR SIMULATED RAINS

Using a drop impact transducer, the relative energy and distribution of rains simulated by five different field simulators at almost the same rainfall intensity were monitored along runoff plots. Evaluation of the impact pulses registered with a highly-resolving X-t-recorder indicated that the rainfall energies of all simulators varied with time and position. Despite this variability, in many cases differences between the different rainfall simulators were significant. It was also found that the energy of one simulator was not typical for natural rainstorms and that that of another one was sensitive to wind conditions. Rainfall simulators with moving nozzles as dropformers showed characteristic periodicities in their energy distribution.