Source: International Atomic Energy Agency – IAEA
Although soil erosion is a natural process and it occurs on all continents, human activities have greatly accelerated it. In general, soil erosion is more common on steep, sloping land. It is often caused by natural factors, including strong wind or heavy rains; however, unsustainable human activity, such as deforestation or improper land management, can accelerate this process by two to three orders of magnitude.
Soil erosion makes land vulnerable to the loss of fertile topsoil and this, together with the losses of associated nutrients and chemicals, is a threat to agricultural production, food security and the environment, mainly water resources. Soil is the source of as much as 95 percent of all agricultural production, so its health and availability impact the quality and quantity of our food. Approximately a quarter of the world’s population directly depends on food produced on degraded land, and every year the rate of degradation is increasing, leading to the annual loss of millions of hectares of land worldwide.
Eroded soil also affects water quality and aquatic life, since soil can be transported by runoff to water courses, such as rivers and lakes, clogging water reservoirs and causing the nutrients washed from the fields to accumulate in water and lead to algae outbreaks. This jeopardizes water quality and harms the habitats of aquatic life. In addition, even in larger reservoirs, such as oceans and seas, sediments may accumulate in large enough quantities to increase turbidity and reduce visibility in nearby waters, further threatening the sustainability of aquatic ecosystems and often leading to die-offs among the flora.
Other consequences of soil erosion include degradation of ecosystem functions, amplified risks of landslides and floods, significant losses in biodiversity, damage to urban infrastructure and, in severe cases, displacement of human populations.