Soil is a fragile foundation of life on Earth, yet climate change has led to faster and more widespread soil erosion.
Erosion is the natural process by which rock and soil wear away over time due to weathering or wind, water or glacial action, or through chemical breakdown through weathering processes.
Erosion refers to the gradual wearing away and transport of rock fragments, soil particles and other materials from their original locations over time, due to various sources such as rainwater runoff, river waters, ocean waves or glacial ice. Erosion may occur as a result of natural processes like physical weathering and chemical weathering as well as wind, water or ice (including glaciers).
Climate, topography and vegetation all play an integral part in erosion. Desert environments tend to be especially susceptible to this form of decomposition because there are no thick grasses or trees to hold back the erosion process.
When we consider erosion, most of us envision water–rainfall, rivers or floodwaters–washing away soil and rocks. Water is one of the primary contributors to erosion as it acts like a fluid, moving from high places down low areas or from wet to dry environments and carrying fine particles of clay or silt far from where they originated.
Wind erosion occurs when shear force exerted by winds on a landform causes its particles to be carried away by the wind, eventually being dusted across other areas and eventually becoming dust. Wind erosion is most severe in arid regions and leads to desertification.
Erosion can be disastrous to both economies and human health, as it strips soil particles rich with essential nutrients, reduces crop production and marketability, causes truck accidents and road closures, increases cleaning costs and absenteeism rates, leads to sand-blasted crops and destroys infrastructure.
Vegetation helps prevent erosion by acting like an anchor for soil and rock particles. As plants die, their roots break apart into loose particles which are easily carried away by rainwater or wind currents; this phenomenon makes semi-arid regions lacking vegetation more vulnerable to erosion than others; climate change also plays a part, with unexpected rainfall or temperature swings being damaging factors on field surfaces.
Ice erosion plays a critical role in shaping Earth’s landscapes. Glaciers, as massive bodies of moving ice that move under their own gravity, serve as effective erosion-causing agents.
Glaciers move at an unprecedented speed, slowly scraping away surface rocks while carrying particles of rock and sediment downstream in their flow to new locations. When this material eventually falls out of their path and settles into deposits called moraines, it creates an unusual landscape called the glacial moraine.
Glacial erosion creates many of the mountainous landforms we know today, such as U-shaped valleys, hanging valleys, cirques, horns and aretes. Glacier-sculpted rocks include large boulders, cobbles and pebbles alongside finer materials such as sand, silt and clay that accumulate.
Mechanical weathering occurs when glaciers ruffle rocks against each other and scrape away at them, leaving behind features such as faceted clasts (rocks with smoothed-off surfaces created from being scraped against each other), striations and grooves, glacial polish and glacial pavements – as well as deposits of sand gravel and rock flour known as glacial till.
Erosion involves the movement of weathered materials by wind and water. Rain works to erode land by splash erosion (rain falling from above and dislodging surface material), river channel erosion (water flowing over and carrying sediment downstream), as well as floodplain erodes and carves out new channels in its wake.
Erosion is a natural process, yet human activities often exacerbate it by altering the natural environment, including activities like land clearing, crop tillage and construction near slopes.
Erosion causes many issues, from loss of soil nutrients and damage to crops and animals, habitat destruction, frequent flooding/waterlogging/landslides/loss of property to frequent flooding/waterlogging/landslides/loss of property. Erosion control is an integral component of land management and agriculture practices such as engineering construction of gabions (large wireframe structures that hold boulders in place) along cliff faces where homes or highways are situated in order to prevent erosion along these edges.