selective corrosion

Selective erosion is a specialized form of erosion which affects specific materials, usually of an agricultural or geological nature. This type of erosion typically does not affect all parts of the landscape, as some areas may remain largely unaffected. It also does not cause significant sediment transport or significant runoff.

Selective erosion is caused by natural forces such as wind, rain, freezing and thawing, as well as human-caused events such as overgrazing, construction and deforestation. Selective erosion occurs when the material is weak and the local geology, land use and climate create an environment that favors the erosion of that particular material. For example, soils can be weakened by plowing, leading to erosion along field boundaries. Similarly, deforestation and overgrazing can weaken vegetation, which can then act as a transporter of specific material in the form of fallen leaves and soil.

Erosion affects the land in a variety of ways. In the short term, it can lead to deposition of materials carried by runoff. In addition, the shape of the land can be altered by the formation of gullies and canyons. Over a longer term, it can lead to an overall reduction in soil fertility and reduce the utility of the land for agricultural or geological purposes.

The potential for selective erosion to cause damage depends on a variety of factors, including the type and degree of vegetation in a given area, the soil texture and soil moisture content, the frequency and intensity of weather conditions that cause erosion, and even human activities such as construction.

Prevention of selective erosion is the best way to limit its effect on the environment. Conservation land use practices are essential, such as proper management of grazing and maintaining a crop rotation system. In areas that are particularly vulnerable to erosion, terracing, strip cropping and windbreaks can be used to reduce its impact. In addition, proper drainage and leaching of soils can help prevent the erosion of specific materials. In severe cases, artificial structures such as dams or bunds can be used to control water flow and protect against erosion.

National wetlands and conservation programs can help protect areas that are especially prone to selective erosion. In addition, correctly managing construction activities such as roadbuilding, mining and flood control, along with proper maintenance of existing structures, can help reduce the effect of human activities on the environment.

Ultimately, understanding the mechanism of selective erosion, and implementing appropriate strategies to reduce its effect, can help protect the stability of the land and the environment it contains.  

Selective erosion is a naturally occurring process that can often be accelerated or amplified by man-made activities, such as land clearing or a decrease in vegetation coverage. Simply put, selective erosion occurs when areas of land become eroded at different rates, resulting in changes in topography. In hilly terrains, this could result in steep slopes where once a landscape was gentle and rolling. On flat land, it might result in gaping ravines or deep gullies where erosion has eaten away at soft soils more quickly.

Many factors can contribute to different levels of erosion between various areas of land. For instance, a deposit of sand in one area might affect the rate of erosion in a nearby area because the particles of sand may protect soils from being pulled away as water rushes through them. Plants also have an important role in preventing soil erosion, as their roots help hold down the soil and their cover helps to reduce the force of runoff. In both of these cases, a reduction or change in either of these factors may precipitate the start or acceleration of selective erosion in an area.

Construction sites where large amounts of soil have been cleared, areas of deforestation and poor agricultural practices can all lead to selective erosion. In addition to creating visible changes in the landscape, this has several other consequences: many areas can become prone to flooding, as less vegetation and soil is able to absorb the water, and this can also end up siltifying lakes and rivers, reducing the amount of sunlight necessary for aquatic animal survival or interfere with the spawning of fish.

Although this is a natural process, human interference with natural vegetation and soil structure can significantly accelerate it and correct management of those areas is essential to preventing the occurrence of this type of erosion.