Changes in raindrop properties due to wind blowing using image processing

The characteristics of raindrops are among the major factors influencing rainfall erosivity. However, the effect of wind blowing on the determining factors of raindrops was not adequately reported. This study aims to measure the characteristics of raindrops under concurrent simulation of rainfall and wind using image processing at different wind velocities under laboratory conditions. For this purpose, changes in particle size distribution, velocity, falling angle, and kinetic energy of raindrops under different wind velocities from 0 to 6 m.s- 1 simultaneously simulated with a constant rainfall intensity of 50 mm h-1 were investigated through processing images taken using a high-speed camera. The results showed significant changes (P < 0.01) in the characteristics of the raindrop in the study wind velocities. By increasing wind velocity, the mean diameter and velocity of the raindrops increased and the falling angle of the raindrops on the soil surface decreased. The mean raindrop diameter, velocity, and the falling angle of the raindrops ranged from 0.93 to 2.17 mm, 3.45 to 7.30 m.s- 1, and 32.04 to 89.83, respectively, for different wind velocities. The mean kinetic energy for different wind velocities also exponentially ranged from 2.50 to 138.60 J. Eventually, external forces for different raindrops ranged from 2.47 to 137.65 mg.mm.s- 1. These results would enhance scientific perceptions of splash and interrill erosions under the concurrent occurrence of rainfall and wind leading to better modeling of soil erosion processes.