Soil erosion is change on the earth’s surface due to external forces like water and wind. The top soil is removed in this process and is deposited in another place. The place can be somewhere nearby or many kilometers away. This is a natural process that might cause problems but will definitely change the topography of a place. Though it is a natural process human beings over the years have increased it manifold creating more problems and effecting dangerous changes all across the globe. Roads, urbanisation, deforestation and extensive agriculture are some of the man made causes for soil erosion.
On-site and Off-site problems
There are problems where the erosion takes place and problems where the deposition takes place; the former is called on-site problems and the latter off-site problems. When the mineral rich top soil is washed away, that are becomes unfit for agriculture and over a period of time it might become a desert region deserted by human beings. Off site deposition of soil can cause clogging of waterways or block the flow or rivers, hamper traffic and more. So there can be problems at both places. There are ways and means to curtail soil erosion; only curtailing is possible not prevention. Natural processes cannot be prevented but man created erosion can be curtailed.
The main natural factors for soil erosion are water and wind. Soil erosion due to water are of different types – sheet, rill gully and bank erosion. In case of sheet erosion the top soil of a large area moves off over a period of time. Rill erosion forms channels while eroding and when it deepens it is called gully erosion. When banks of the river erode it is called bank erosion. The prominent and common bane of soil erosion is the loss of top soil and along with it the natural nutrients. If cultivation is on then it can take away the seeds and plants and the fertilizers with it.
Problems due to soil erosion
Off site sedimentation can block water channels, spoil fish habitat and cut transport links. Pesticides transported can be harmful for other living beings or soil. Wind erosion does the same work but what is carried off really travels more distance. Where winds are strong there is less vegetative cover as wind blows it off time and again. Crops are easily ruined because of wind. The plants are prone to diseases and the quality of the yield goes down. Timely activities like sowing, ploughing and harvesting are hampered by wind erosion.
Deforestation is another main reason for soil erosion. Trees hold on to the soil and when these trees are cut the soil has no hold and is easily carried away by water or wind. This in turn makes way for trees nearby to succumb to vagaries of weather. Man can do a lot to stop soil erosion especially that is created by man. Tilling is another reason for soil erosion. Extensive agriculture can be controlled, deforestation can be controlled. If these two are implemented well there will be a drastic drop in the problems created by soil erosion.