Erosion is the process of wearing away and shaping landforms through small fragments moving from place to place over time.
Some forms of erosion occur quickly – for instance, mudslides can happen within minutes.
Wind and gravity are primary causes of erosion; however, water, glaciers, and living things may also contribute to its progression.
Water
Water erosion is one of the primary contributors to land degradation. Its powerful force can erode away rocks and soil, as well as cause landslides. Water erosion occurs most commonly in mountainous regions where glaciers slowly erode away at the land’s surface.
River water flows downstream eroding its banks and bed. If a river floods, its power of erosion increases significantly and carries along massive quantities of sediment downstream, creating river deltas or other landforms in its wake.
Natural factors also contribute to erosion. For instance, rough streambed surfaces may increase friction and slow river speed, slowing its progression downstream. Human activities also play a part in erosion; for example tillage techniques used by farmers when prepping seedbeds can dismantle soil structure quickly leading to rapid erosion. Deforestation, roads and industrial agriculture can all cause erosion.
Wind
Wind erosion occurs when wind blows across soil and transports the material away, whether that be just a few feet or thousands of miles. This process of mechanical erosion distinguishes it from weathering which doesn’t involve movement at all.
Wind erosion occurs most commonly in areas lacking natural vegetation to hold down the soil or when crops have been harvested and left exposed for weeks or months postharvest, but can also happen where livestock grazing or land clearing practices such as clearcutting have stripped the ground of grasses and ground covering plants that help protect it.
Erosion by wind can be an enormously destructive force. It can reduce crop yields, pollute air and water supplies, degrade the quality of soil and create beautiful geological formations such as sand dunes and mountain ranges – but at times can even introduce dangerous pollutants into drinking water supplies.
Ice
Ice can be an immensely powerful force that erodes rock. Glaciers tumbling down mountains or across landscapes are particularly effective at this, moving rapidly while scraping against rocks and sediment beneath them before picking up and transporting these materials away.
Glaciers erode the ground through processes known as abrasion and plucking. Abrasion involves grinding away at rocks’ surfaces while plucking involves pulling boulders and sediment clinging to them away from them onto its surface by their glacier’s momentum.
These processes can create some intriguing landforms. A “roche moutonnee,” formed by glacier movement, is one example. Nunatuks are another such landform resulting from interactions between glacial scouring and basal slippage processes that form round peaks with irregular edges that provide protection from climate change.
All these processes can lead to erosion due to their combination of forces such as water, wind, ice and gravity. When these forces come together, erosion creates stunning landforms found across the globe.
Soil
Soils serve as the Earth’s delicate skin, supporting life on this planet. Erosion of soil damages ecosystems and human activities alike; including agriculture. Erosion destroys topsoil which reduces crop yields while transporting organic matter, soil particles, fertilizers into rivers and waterways where it pollutes aquatic habitats and pollutes aquatic environments. Erosion also degrades quality soil which leads to its stability being diminished as its texture diminished by erosion.
Erosion is a natural phenomenon, but certain human activities can exacerbate it. Direct impacts include deforestation and unsustainable agricultural practices that alter topsoil and make it more susceptible to erosion; indirect consequences include mining, road building and climate change – which all increase soil erodibility.
Weathering is the natural process by which rocks and soil gradually disintegrate into smaller pieces and are carried away by erosion processes. Living things, like plants, may also contribute to this erosion process by growing in cracks in rocks and increasing their size to release more rock particles for erosion to carry away.