Natural soil erosion
Soil erosion may occur natural by water or wind dispersing particles of soil. Water erosion may reduce overall quality of soil, reduce the capacity of the soil to absorb water, increase occurrences of flooding and water based illnesses, and increase the amount of sediment in waterways. Water erosion is affected by rainfall, topography, and the type of soils and vegetation present in the area where it occurs. Wind erosion often has a lesser effect than water erosion, as most soil is stable enough to withstand wind erosion better than water erosion.
Anthropogenic soil erosion
Human activities over hundred of years have contributed greatly to climate change, the increasing temperature of the earth’s atmosphere. With these increasing temperatures, the capacity of the atmosphere to hold water vapor has likely increased and therefore storm severity may have as well. Changing weather patterns have likely already contributed to soil erosion and may continue to do so at a larger scale as time goes on.
Improper and unsustainable land use by landowners and management have also contributed greatly to soil erosion. Agricultural practices and resource harvesting, such as intensive planting on hillsides, intensive deforestation, particularly on steep slopes, overgrazing of cattle and overuse of livestock trails are only a few of these practices that have degraded the land. Making the situation worse, many landowners will abandon degraded property instead of taking steps to revive the area, creating a negative feedback loop of unsustainable management and land degradation.
In the Nyando River Basin in Kenya, soil erosion has been increased severely by sand harvesting. Sand harvesting is a constant driver of soil erosion in this area, as sand is harvested for construction purposes and there is therefore always a demand for it. The harvesting of sand by Kenyan people increases the rate of erosion tenfold, making it likely the greatest contributor to gully erosion in the area. Sand harvesting is hard work but because there is such a demand for the product, both elderly people and youth, as young as 8 years of age and maybe even younger, may be seen doing this backbreaking work.