Anyone who lives near water or has a slope of any kind in their front or back yards, are prone to erosion. It is after all a geological process in which earthen materials are worn away and transported by natural forces such as wind and ice.
According to the World Wildlife Federation, half of the planet’s topsoil has been lost in the last 150 years. How is that possible? Imagine a field stripped for development or a farm cleared for the next season and a slight breeze of just 10 miles per hour blows through it. Millions of topsoil particles are picked up and displaced. Now increase the wind by just 5 miles per hour where dust bunnies can be observed, and you get the picture.
Biggest Erosion Culprit
But the biggest culprit for erosion is water. If soil is not protected, water erosion is caused when raindrops fall on bare ground or sparsely vegetated soil and detach soil particles. Each large raindrop is a mini explosion on soil and once the particles are dislodged, water flowing over the ground picks up the particles and carries them away. As water runoff picks up velocity, channels are formed, and they detach more soil particles. These channels cut rills and finally, gullies into the land. For scale, you can still drive over a rill but a gully you cannot.
So, what happens to these particles picked up by wind or water? When water or wind velocity slows to a sufficient degree, and for a sufficient period, it allows the particles to settle out of suspension, otherwise known as sedimentation. Water only flows one way and at the end of that downhill, sediment settles. The end-of-the-road for soil particles are often rivers, lakes, ponds or the end of your driveway!
Natural or geological erosion has occurred at a relatively slow rate since the earth was formed. Our various landscapes around the country are proof of it. This form of erosion accounts for about 30% of all sediment in the USA. However, accelerated erosion accounts for 70% of all sediment generated. There are many culprits: Agricultural cultivation, forest harvesting, rangeland grazing, surface mining, urban development and highway construction to name a few. Basically, any activity that disturbs land can increase the natural erosion rate. In fact, everyone acre stripped equals one truck load of topsoil lost.
Not all soils are equal. Texture, structure, organic content and soil permeability determine loss rates. Soils can contain high percentages of silt, a very fine sand that is the most erodible. As the clay and organic matter content of these soils increase, erodibility decreases. Clay acts as a binder of soil particles and tends to resist erosion. However, once detached, they are easily transported by water and settle out slowly due to the heavier weight.
The easiest solution? Vegetation. It shields the soil surface from the impact of falling rain, holds soil particles in place, maintains the soil’s capacity to absorb water and removes subsurface water through evapotranspiration. Second, staging (scheduling) the removal of vegetation on large areas to reduce exposure and duration of naked land would aid in erosion prevention. Finally, the installation of any geotextile covering as soon as possible after clearing will go a long way to protect topsoil.
By Michael Cordier, Director: Business Development & Strategy, Landshore Enterprises LLC, 188 Triple Diamond Blvd., Suite A4, North Venice, FL 34275 firstname.lastname@example.org ©2018