Érosions

Érosions are processes that remove and transport material from surfaces, including soil and rock. In French, érosions is the plural form of erosion, and in English discussions the term describes the same broad set of processes across environments. Erosion shapes landscapes, reduces soil fertility, and moves sediment to rivers, lakes, or coastal zones.

Erosional processes are commonly categorized by their primary agent: water, wind, ice, chemical reactions, or biological activity. Water erosion includes sheet, rill, and gully erosion; wind erosion involves deflation and abrasion; glacial erosion arises from ice movement; coastal erosion is driven by waves and tides; chemical erosion involves dissolution and carbonation. Some frameworks also include mass-wasting processes that move material downslope under gravity as related to erosion.

Causes include natural factors such as rainfall intensity and runoff, wind speed, and gravity, along with human activities such as deforestation, farming, overgrazing, urban development, and mining. Erosion can reduce soil depth, degrade water quality, and reshape landforms like valleys and cliffs, while sediment accumulation affects rivers and coastal systems.

Management aims to reduce erosion through practices such as cover crops, reduced tillage, contour farming, terracing, windbreaks, riparian buffers, reforestation, and soil-conservation farming. Coastal erosion may require dune stabilization or shoreline protection. Erosion assessment uses rates of soil loss and models such as the Universal Soil Loss Equation (USLE) and its revisions, together with remote sensing and field measurements.