Erosion is a natural process, but human activities can speed it up considerably. Examples include intensive agriculture, deforestation and road construction projects as well as reduced vegetation coverage in an area which helps hold soil together during rain and wind events.
Physical erosion refers to the wear-and-tear wear-off of rocks and Earthen materials by moving water, ice or wind.
Water
Force of water washing over land is the main factor contributing to erosion. Rainwater flowing down slopes transports sediments containing soil particles and deposits them elsewhere; currents also erode rocks by scouring, particularly where resistance such as boulders or cliffs exist.
Water erosion can also be accelerated by waves crashing against coastlines and wind-blown sand and rock; such as Badain Jaran in China’s Gobi Desert where such dunes have grown into immense heights through this process.
Natural erosion will occur without human interference; however, humans can significantly accelerate it by disturbing the soil or drying it out. Farming, grazing, mining, road construction and deforestation are all activities which increase soil erosion rates; such activities include farming, grazing, mining, road construction and deforestation as major culprits of soil loss. Aggressive farming techniques that disturb the ground or dry it out accelerate this phenomenon even more, leading to nutrients-rich soil entering waterways where it can clog streams or pollute drinking water supplies as well as chemicals from crops sprayed over fields contaminating drinking water supplies as well.
Wind
Wind erosion occurs most frequently in flat, bare areas without enough vegetation to retain soil in place or that have been ploughed up for agriculture. Soil type also plays an important role: loamy soil that’s loose and sandy is most vulnerable, while dense clayey soil with structure makes less of an impactful statement about wind erosion.
Wind erosion causes soil to shed small bits of rock and other materials that are then carried by the wind and eventually deposited somewhere nearby, such as in a river bed, or further away if washed into the ocean. This process is known as deposition.
Sand and dust blown by the wind can harm plants and commercial crops, decreasing yields while also leading to asthma attacks and other lung-related ailments in people living nearby. This issue is especially pertinent in arid climates; one dramatic example being the “Dust Bowl” of 1930s where severe wind erosion due to drought conditions combined with poor agricultural management led to mass migrations of people from these areas.
Ice
Glaciers, found mostly near the poles and high in mountains, can be powerful agents of erosion. When glaciers flow down mountains they wear away at rock surfaces leaving deposits of sand and pebbles known as sediment behind, reshaping landscape features such as U-shaped valleys, horns and moraine. Glaciers also cause further erosion through processes known as plucking and abrasion which cause further landform change.
Erosion along Arctic coastlines can also be caused by permafrost melting due to rising temperatures that lead to its thawing and rising sea levels, as well as by melting permafrost that exposes frozen ground (permafrost) being washed over by rising sea levels.
Erosion can cause many issues, from soil degradation and loss of valuable farmland, to habitat destruction for animals and plants. Erosion also destabilizes river and stream channels leading to floods; alters water quality by transporting pollutants; human activities can add further problems such as land clearing for agriculture or overgrazing livestock – contributing further to erosion.
Vegetation
Plants can help combat erosion by binding soil with their roots, absorbing water to decrease runoff, providing cover and creating natural barriers. Furthermore, they help break up rocks or minerals that might otherwise erode away.
Physical erosion occurs when rocks become smaller or smoother due to weathering processes or when they crumble and are moved by wind, water or glaciers. Erosion often creates spectacular landforms like canyons, gorges and cliffs while mass wasting is caused by downward movements of soil, rock and vegetation, reshaping mountains and destroying communities along its path.
Wind erosion works in two ways. Either it removes dust, sand and gravel through deflation or wears away surfaces with its fast movements (abrasion). Wind erosion can form towering sand dunes like those found in China’s Badain Jaran section of Gobi Desert as well as shape rocks into distinct forms like arches, sea stacks, chimneys or polish them to an “desert varnish” appearance.