Soil splash phenomenon - how much energy of raindrop is used for transportation of the splashed material?

Splash erosion is one of the form of water erosion, where the falling raindrops hit the soil surface and result in detachment and ejection of splashed material, and transport thereof over different distances. This process causes the loss of soil material, the breakdown of soil aggregates or is responsible for the displacement of microorganisms, pathogens, and pollutants within the ejected particles. The ejection of a mixture of solid (soil) and liquid (water) phases is one of the aspects of the energy dissipation of the impacting drop during the splash. Therefore, the aim of the study was to present the method for the estimation of the falling drop energy that was used for the transportation of the ejected material, while considering that such material was a mixture of solid soil particles and water droplets and therefore, “two-phase”.

The use of an innovative multi-method approach allowed for the characterization of ejected particles during soil splash phenomenon affected by a single drop impact. The mass measurements provided by a splash cup and image analysis method based on high-speed cameras gave the possibility to determine average density of the splashed material, the number of ejected particles, their sizes and masses, and their ejection velocities. Consequently, it enabled the calculation of the summed kinetic energy of ejected particles expressed as a percentage of falling drop energy transferred to splashed material. Based on the obtained results, this value ranged from 1% to 14 % and was strongly dependent on soil texture as well as initial moisture content. The study should be considered, in the context of physical modelling of splash erosion, as an important step for calculation of the energy balance of a single drop impact, i.e., the energy dissipation allowing for the determination of which processes absorb the kinetic energy of the falling drop during soil splash phenomenon.

 

This work was partly financed from the National Science Centre, Poland; project no. 2022/45/B/NZ9/00605.

 

References:

Beczek M., Mazur R., Ryżak M., Sochan A., Polakowski C., Beczek T., Bieganowski A.: How much raindrop energy is used for transportation of the two-phase splashed material? GEODERMA 425, 2022

Beczek M., Ryżak M., Sochan A., Mazur R., Polakowski C., Bieganowski A.: A new approach to kinetic energy calculation of two-phase soil splashed material. GEODERMA 396, 2021