Erosion control methods? What is soil erosion and soil degradation? Although soil erosion is a natural process, human activities over the past decades have greatly accelerated it. In fact, according to the UNESCO, land degradation is undermining the well-being of two-fifths of humanity, driving species extinct and intensifying climate change. According to a senior UN official, all of the world’s topsoil could be gone within 60 years.
Rainwater also mixes with chemicals as it falls from the sky, forming an acidic concoction that dissolves rock. For example, acid rain dissolves limestone to form karst, a type of terrain filled with fissures, underground streams, and caves like the cenotes of Mexico’s Yucatan Peninsula. Back up on the mountains, snow and ice build up into glaciers that weigh on the rocks beneath and slowly push them downhill under the force of gravity. Together with advancing ice, the rocks carve out a path as the glacier slumps down the mountain. When the glacier begins to melt, it deposits its cargo of soil and rock, transporting the rocky debris toward the sea.
In rivers and estuaries, the erosion of banks is caused by the scouring action of the moving water, particularly in times of flood and, in the case of estuaries, also by the tidal flow on the ebb tide when river and tidewater combine in their erosive action. This scouring action of the moving water entrains (that is, draws in and transports) sediments within the river or stream load. These entrained sediments become instruments of erosion as they abrade one another in suspended transport or as they abrade other rock and soil as they are dragged along the river bottom, progressively entraining additional sediments as long as the river’s volume and velocity of the stream continues to increase. As the velocity of the river decreases, the suspended sediments will be deposited, creating landforms such as broad alluvial fans, floodplains, sandbars, and river deltas. The land surface unaffected by rivers and streams is subjected to a continuous process of erosion by the action of rain, snowmelt, and frost, the resulting detritus (organic debris) and sediment being carried into the rivers and thence to the ocean. Read additional info on what is erosion wiki.
Soil erosion, that is, the process that transforms soil into sediments, is one of the major and most widely spread forms of land degradation (Lal 2014; Weil and Brady 2017). It encompasses the destruction of the physical structure that supports the development of plant roots. Moreover, surface soil removal may result in substantial nutrient and water losses, as well as in the decrease of productivity and the increase of pollution of surface waterways. Soil erosion impacts thus the sustainability of ecosystems and the provision of ecosystem services. Soil conservation efforts address concerns with these impacts and meet the increasing needs for food and raw materials (Hurni et al. 2008).
Soil Conservation is the name given to a handful of techniques aimed at preserving the soil. Soil loss and loss of soil fertility can be traced back to a number of causes including over-use, erosion, salinization, and chemical contamination. Unsustainable subsistence farming and the slash and burn clearing methods used in some less developed regions can often cause deforestation, loss of soil nutrients, erosion on a massive scale, and sometimes even complete desertification.