Modelling water transfer by rain-splash in a 3D canopy using Monte Carlo integration

Rain-splash is a very effective process in the short distance dispersal of biotic and abiotic particles leading to potential biological or chemical contamination within crop ecosystems. A physical approach to simulate water transfer by rain-splash in a 3D canopy structure is presented. This new approach is based on the explicit parameterisations of the mechanisms such as raindrop propagation, production and transport of splash droplets and their interception by canopy elements. The model theory and its numerical solution were based on the Monte Carlo integration technique. The calculation of droplet trajectories was validated by comparison with the previous published measured data (R²=0.99 for the terminal velocity and R²=0.93 for the distance travelled by droplets). Simulated patterns of splash dispersal through artificial canopies consisting of vertical cylinders compared well with measured patterns (R²=0.90). This new modelling approach is promising for studying particle dispersal by rain-splash in complex canopy structures.