Erosion is the natural process of moving soil or rock from one location to the next, whether that movement be millimeter-scale or extended over many kilometers.
Erosion can be caused by several forces, including weathering, water, wind and glaciers. Other important causes may include topography, vegetation or tectonic activity.
Weathering
Weathering is the process by which rocks and minerals break down naturally over time through physical or chemical means without transportation of the material involved.
Erosion occurs when materials are dislodged from their original location by natural forces such as wind, water or glaciers – for instance if you see a mountain covered with sand and gravel it indicates erosion has taken place.
Climate, topography, vegetation and plate tectonics all play a part in erosion; over time these forces wear away at mountains, rivers, hills, coastlines and roads alike. Agriculture, deforestation and road construction all speed up erosion’s progress; it may even cause floods, mudslides or soil loss if left uncontrolled – yet there are ways to control and slow erosion; for instance “splash erosion” caused by raindrops falling can be prevented with proper construction techniques.
Water
Erosion occurs when small pieces of rock and soil are removed from Earth’s surface by means such as wind, water or glaciers and carried away to be deposed elsewhere – this process is known as erosion.
Rain, melting snow, flowing rivers and glacier movement all play a part in erosion. The speed and amount of erosion depend on factors like land size and shape; amount of vegetation cover on ground; cracks in rock; etc.
For example, streams that flow over steeper slopes erode more rapidly than streams flowing across gentle ones. Rivers erode faster than lakes; fast-moving rivers even more so due to being able to scour away more rock and soil from their path.
Wind
Wind erosion is the process of transporting and depositing soil particles by the wind. It occurs most frequently in flat, barren areas with limited or no natural vegetation and has the ability to cause irreparable harm by moving nutrients-rich soil away from its original location and depositing it elsewhere.
Wind can carry clay- and silt-sized sediment particles vast distances before being deposited on surfaces such as beaches. Wind also erodes rocks to produce ventifacts – such as those that give Arches National Park in Utah its unique form.
Wind erosion depends on a number of variables, including weather and soil condition. Vegetation helps mitigate wind erosion as its roots anchor soil into place. On the other hand, human activities like agriculture may increase wind erosion in a region.
Glaciers
Glaciers are enormous rivers of ice that travel down mountain slopes, carving U-shaped valleys and other glacial landforms into their path as they flow.
Glacial outwash refers to the process by which glaciers deposit rocks and sediment when they melt, leaving behind deposits called glacial outwash.
Abrasion is also an integral component of glacier terrain formation, as the melting ice and its load of broken rocks rub against bedrock to act like sandpaper, smoothing and polishing its surface.
Mechanical weathering erodes glacier sides, loosening large pieces of rock debris known as erratics to fall off into glacial valleys and form piles known as moraines, where they accumulate after melting glaciers have vanished.
Human Activity
Human activity often causes erosion by altering vegetation of an area. When people clear away trees and plough up grass for farming or development purposes, leaving soil exposed to strong winds and rainstorms. Plants – particularly tall grasses and shrubs – provide support in holding back erosion.
Physical erosion occurs when rocks and soil are worn away through mechanical and chemical forces such as mechanical forces and water currents, wind or ice, respectively. Water, wind, ice and river rocks play their parts as well – river rocks have the unique property of constantly being worn smooth by being constantly in contact with each other and carrying sediment deposits with them.
Erosion is a natural process, but humans can exacerbate it quickly. Erosion results in topsoil loss from land parcels and reduces their productivity as well as polluting air and water supplies.