Influence of selected physicochemical properties of soils on phenomena occurring on the soil surface under impact of a hitting water drop

Research

Influence of selected physicochemical properties of soils on phenomena occurring on the soil surface under impact of a hitting water drop

Leader: DSc Magdalena Ryżak

Team: PhD Eng Agata Sochan; MSc Eng Michał Beczek; MSc Eng Rafał Mazur

 

Soil is a natural product of the top layer of the Earth’s crust and plays an important role in the functioning of many ecosystems. It is one of the key factors in the water cycle, as well as a factor shaping the landscape. It is also the basis for agricultural production. Soil and other components of the environment are exposed to a variety of factors that may cause its degradation. One of these factors is water. Erosion may begin already at the time of the fall of a single raindrop on the surface of the soil. Detachment of the soil material from the surface due to the impact of a drop of water is called splash. Methods used so far for measuring erosion have been based mostly on the analysis of the weight of the soil material that has been transferred as a result of splash. The measurement was only possible when many drops fell on the soil and the mass of material collected was sufficiently large to be measurable.

 

The ongoing research task is aimed at exploration of factors that determine the susceptibility of soil to erosion. Investigation and determination of the influence of the physicochemical properties of soil on splash will provide a better understanding of the phenomenon itself and in the long term may contribute to reduction of erosion, which has a negative impact on the soil environment.

 

Application of high-speed cameras (recording rate of min. 2,000 frames per second) for measurement of the splash phenomenon will elucidate the course of the impact of a single droplet on the soil surface. Selection of varied soil material (in terms of both particle size distribution and physicochemical properties) will help to find the relationship between different properties of the soil and its susceptibility to erosion. Application of the single-drop method developed in the Institute of Agrophysics for investigation of the splash phenomenon will reveal the course of events at a certain initial moisture content of the soil. This moisture at the site of the drop fall varies significantly after the fall of each successive drop.

 

As part of the task, the influence of particle size distribution of the soil, soil type, initial moisture content, and wettability on the susceptibility of the soil to splash will be investigated. Single drops will be applied on soil placed in aluminium rings. The splash phenomenon will be recorded using a set of 3 cameras (Phantom Miro M 310). After recording the phenomenon, the number of detached soil particles and/or droplets that have splashed as well as their trajectories and speed will be analysed. At higher moisture content, the shape, time of formation, and rupture of a crown formed will be analysed.

 

References

  1. Mouzai L., Bouhadef M.: Water drop erosivity: Effects on soil splash. Journal of Hydraulic Research 41(1), 61-68, 2003.
  2. Ryżak M., Bieganowski A.: Using the image analysis method for describing soil detachment due to the single waterdrop impact. Sensors 12, 11527-11543, 2012.
  3. Ryżak M., Bieganowski A., Polakowski C.:  The problem of reproducibility of measurements using a single drop splash of simulated precipitation. PLoS One 2015, Vol. 10(3): e0119269, doi:10.1371/journal.pone.0119269
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