![]() ![]() The widespread occurrence of water erosion combined with the severity of on-site and off-site impacts have made water erosion the focus of soil conservation efforts in Ontario. This fact sheet looks at the causes and effects of water, wind and tillage erosion on agricultural land. Soil compaction, low organic matter, loss of soil structure, poor internal drainage, salinisation and soil acidity problems are other serious soil degradation conditions that can accelerate the soil erosion process. Soil erosion can be a slow process that continues relatively unnoticed or can occur at an alarming rate, causing serious loss of topsoil. Soil erosion reduces cropland productivity and contributes to the pollution of adjacent watercourses, wetlands and lakes. Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere “on-site” where it builds up over time or is carried “off-site” where it fills in drainage channels. The erosive force of wind on an open field.Įrosion, whether it is by water, wind or tillage, involves three distinct actions - soil detachment, movement and deposition. The erosive force of water from concentrated surface water runoff. In agriculture, soil erosion refers to the wearing away of a field’s topsoil by the natural physical forces of water (Figure 1) and wind (Figure 2) or through forces associated with farming activities such as tillage. ![]() The small amount of momentum transferred explains why the large amounts of energy present in rainstorms cause only a small proportion of total soil erosion by water processes.Soil erosion is a naturally occurring process that affects all landforms. ![]() The data produced demonstrates that, for example, for a 3.7-mm raindrop impacting a 150-160 µm sand bed at 6.2 m/s, only approximately 2% of the momentum of the rain drop gets transferred to the ballistic ejection of dry sand particles from the crater edge. To investigate the interaction that occurs, three different techniques are used: i) High speed imaging of the interaction, looking at the dynamics of both the water and the sand ii) Three dimensional, time resolved particle tracking of the grains ejected from the sand bed during the event iii) Surface profiling of the crater produced by the impact and the large clumps of sand transported from the crater edge. However, for this study, all of these variables are kept as constant as possible, with multiple runs made of the same individual interaction, in order to examine the complexity and variability of the event. The nature of the interaction that occurs between the water and the sand is defined by a large number of variables such as droplet size, impact velocity, fluid viscosity, surface tension, grain size, grain shape and packing density. The study focuses on quantifying the ejection of particles from the bed through momentum transfer and the resultant change in the morphology of the bed caused by the impact. The work presented in this study examines the interaction that occurs between an impacting water droplet and a bed of loose, graded sand, with the aim of providing further insight into the transfer of energy between them. However, even though splash transport has received considerable attention over the years, little is still known about the transfer of momentum between raindrops and soil particles, with only a few recent studies investigating the fundamental interactions involved. The transportation of soil particles through the process of raindrop impact is a significant mechanism within the process of soil erosion.
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