Erosion is the natural process by which rocks, soil and mud are transported from one area of Earth’s surface to another by moving in its course; as opposed to weathering which involves breaking down rocks but no movement between locations.
Water, wind, and ice are the three primary forces responsible for erosion; however, human activity may also contribute to its spread.
Water
Rainwater dislodges soil particles from their original position during a rainfall event and this process of erosion occurs.
Erosion also breaks apart and dissolves rock through a process known as weathering, creating caves, streams and canyons in its wake. Erosion may happen faster in areas with exposed soil or extreme weather conditions.
Rapid erosion can destroy farms and pollute waterways with sediment that clogs them with sediment, leading to fish population reductions and desertification of once fertile land. Smart farming practices and returning natural vegetation can help mitigate erosion; however, climate change and deforestation have amplified its effect.
Wind
Wind erosion occurs most commonly in arid regions where vegetation is scarce, leading to periodic dust storms in desert environments. Sand storms also result from this process.
Roots keep soil from eroding physically, slowing physical erosion. But when roots are removed for agricultural use, physical erosion becomes an even bigger issue and reduces both productivity and quality of water and air resources.
Climate is a key contributor to erosion as it influences rainfall patterns, increasing or decreasing as needed. Heavy rainfall may exacerbate erosion problems if it falls at an unsuitable time or when vegetation hasn’t fully taken hold. Drought can exacerbate erosion further by forcing plants out that hold back soil in its place.
Ice
Ice erosion occurs when glaciers grind down rocks and pebbles they carry, wearing away at them by both abrasion and plucking, leaving behind mountains, valleys and other forms of landscape features that they form from.
Glaciers often scour valley floors to produce smooth surfaces known as glacial pavements, while glacial erosion scratch deeply into rocks to form long parallel grooves known as striations grooves.
Glaciers use their abrasive action to transform mountain landscapes by clearing away dirt, sand and small stones from their surfaces, leaving behind bowl-shaped depressions known as cirques at higher elevations; when multiple cirques form on one mountain peak they may cause its side to be eroded away, producing sharp-sided peaks known as horns. Other glacial features include moraines which contain boulders deposited by glaciers.
Plants
Plants bind soil together through their roots, helping prevent erosion by slowing the flow of water. Without plants, erosion would be far worse as wind and water could easily blow loose dirt and sand from exposed ground surfaces away. Trees, shrubs and grass serve as natural solutions against erosion by holding onto soil in place.
Bioerosion, or plant growth-mediated physical erosion, occurs when living organisms wear away at rocks or earthen materials without altering their chemical makeup.
Long-term erosion can strip a landscape of its life and charm, diminish crop productivity and lead to the loss of topsoil that provides crucial nutrition. Farmers can reduce erosion by leaving protective covers in place during weather that causes it, planting cover crops like alfalfa or winter wheat after annual row crop harvests, and using other techniques like planting protective covers such as alfalfa seed to form protective barriers between erosion zones.
Human Activity
Weathering involves weathering away of Earth’s surface materials while erosion involves movement of them. Erosion occurs when water, wind, ice or gravity move the sediment out from one location and transport it elsewhere – for instance along a mountainside or riverbed or globally by glaciers moving across rocks and soil.
Erosion is another natural process that can create fascinating geologic features. For instance, erosion can change the bed of a stream such that its depth narrows and deepens as it flows downstream – this creates a beautiful waterfall called a cataract.
Human activity can increase erosion rates 10-to 100 times more rapidly than natural processes alone. This occurs due to deforestation, plowing fields and grazing livestock disrupting roots that hold soil particles together causing further erosion while contributing to increased sediment pollution in streams and rivers.