What is soil erosion?
Soil is naturally removed by the action of water or wind: such ‘background’ (or ‘geological’) soil erosion has been occurring for some 450 million years, since the first land plants formed the first soil. Even before this, natural processes moved loose rock, or regolith, off the Earth’s surface, just as has happened on the planet Mars. In general, background erosion removes soil at roughly the same rate as soil is formed. But ‘accelerated’ soil erosion — loss of soil at a much faster rate than it is formed — is a far more recent problem. It is always a result of mankind’s unwise actions, such as overgrazing or unsuitable cultivation practices.
Soil is naturally removed by the action of water or wind: such ‘background’ (or ‘geological’) soil erosion has been occurring for some 450 million years, since the first land plants formed the first soil. Even before this, natural processes moved loose rock, or regolith, off the Earth’s surface, just as has happened on the planet Mars. In general, background erosion removes soil at roughly the same rate as soil is formed. But ‘accelerated’ soil erosion — loss of soil at a much faster rate than it is formed — is a far more recent problem. It is always a result of mankind’s unwise actions, such as overgrazing or unsuitable cultivation practices. These leave the land unprotected and vulnerable. Then, during times of erosive rainfall or windstorms, soil may be detached, transported, and (possibly travelling a long distance) deposited.
Soil erosion is a term for soil either gradually being taken from the land, or very suddenly being washed away or blown away. The gradual erosion of soil from the land is something which is a natural process. Water and wind naturally remove soil from the land, but usually at a rate which is the same as soil is formed, so some soil is taken away but this is replaced. Soil erosion which is sudden has a negative impact on the land. Sudden erosion is caused by extreme rainfall literally washing away soil, rivers bursting their banks and taking soil with them to the sea or by tsunamis. tornadoes etc. When this happens then the soil is not replenished and the land is less productive so crops do not grow as well. Soil contains many nutrients which are beneficial to crops or to stock feeding off the land, so the land cannot immediately recover after widescale erosion has occurred.
Why is it considered a pollutant? Read on… WHAT IS SOIL EROSION? Erosion is a natural process by which the surface of the land is worn away by water, wind or chemical action. Accelerated erosion is the removal of the surface of the land through the combined action of human activities and natural processes at a rate greater than would occur from natural processes alone. IS SEDIMENT REALLY A POLLUTANT? A certain amount of erosion and sediment occurs naturally. Because it is a natural process, nature is able to assimilate naturally occurring sediments without permanent adverse effects. Adverse effects most often result from accelerated erosion due to earth disturbance activities such as surface mining, agricultural plowing and tilling, construction, and timber harvesting operations. Why is sediment pollution harmful? Fish have gills which extract oxygen from the water. These gills can become clogged when the water transports excessive amounts of sediment. Sediment can cover fish eggs an
