a. Splash Erosion: It is the detachment and airborne movement of small
soil particles caused by the impact of rain drops on soil.
soil particles caused by the impact of rain drops on soil.
b. Sheet Erosion: According to Carla (2008) it is the
detachment of soil particles by raindrop impact and their removal of down-slope
by water flowing over land as a sheet instead of indefinite channel or rills.
The impact of the raindrop
detachment of soil particles by raindrop impact and their removal of down-slope
by water flowing over land as a sheet instead of indefinite channel or rills.
The impact of the raindrop
breaks apart the soil particles of clay, silt and
sand into the soil pores thus reduce infiltration. Once the rate of falling
rain is faster than infiltration, run-off takes place. There are two stages of
sheet erosion; the first is rain splash, in the soil particles are knocked into
the air by raindrops impact. Secondly, the loose particles are moved down-slope
by broad sheets of rapidly flowing water-filled with sediment known as sheets
flood. This stage of sheet erosion is produced by cloud burst, sheet floods
which commonly travel short distances and last only for a short time.
c Rill Erosion: According to Henderson (2006), it refers to the
development of small ephemeral, concentrated flow path, which function as both
sediment source and sediment delivery system for erosion in hill slope. Where
water erosion rates on disturbed up land area are greatest, rills are active. Where
precipitation rates exceed soil infiltration rates, run-off causes more erosion
than the initial raindrop impact. This type of erosion occurs in Agbor drainage
system after a heavy down pour.
development of small ephemeral, concentrated flow path, which function as both
sediment source and sediment delivery system for erosion in hill slope. Where
water erosion rates on disturbed up land area are greatest, rills are active. Where
precipitation rates exceed soil infiltration rates, run-off causes more erosion
than the initial raindrop impact. This type of erosion occurs in Agbor drainage
system after a heavy down pour.
d Gully Erosion: Bunnet and
Okunrotifa (2003), also called ephemeral, gully erosion, occurs when water
flows in narrow channels during or immediately after heavy rain or during
melting snow. This is particularly noticeable in the formation of hollow ways
where tarmac and old rural roads has over many years become much lower than the
surrounding field. A gully is deep, ranging from 1 to 2 feet (0.61m) to as much
as 75 to 100 feet (30m). According to Morgan (2006), it is more localized and
occurs when heavy rainfall rushes down a steep slope, cutting deep grooves into
the land. The grooves become deepened and widened to form gullies.
Okunrotifa (2003), also called ephemeral, gully erosion, occurs when water
flows in narrow channels during or immediately after heavy rain or during
melting snow. This is particularly noticeable in the formation of hollow ways
where tarmac and old rural roads has over many years become much lower than the
surrounding field. A gully is deep, ranging from 1 to 2 feet (0.61m) to as much
as 75 to 100 feet (30m). According to Morgan (2006), it is more localized and
occurs when heavy rainfall rushes down a steep slope, cutting deep grooves into
the land. The grooves become deepened and widened to form gullies.
e River Bank Erosion: According to Olatunji (2003), it is the wearing
away of the banks of a stream or river. It is distinguished from changes on the
bed of the water course, which is referred to as scour erosion and changes in
the form of river banks. May be measured by inserting metal rods into the banks
and making the position of the bank surface along the rods of different times.
This erosion generates movement of water and rise in water level during
flooding.
away of the banks of a stream or river. It is distinguished from changes on the
bed of the water course, which is referred to as scour erosion and changes in
the form of river banks. May be measured by inserting metal rods into the banks
and making the position of the bank surface along the rods of different times.
This erosion generates movement of water and rise in water level during
flooding.
f Coastal Erosion: Much like river banks erosion, it occurs along
sea and ocean coast during flooding, leading to sea rise and flooding.
sea and ocean coast during flooding, leading to sea rise and flooding.
g Wind Erosion: Birkeland (2006) states that wind erosion is more
likely to occur in dry area where soil
is loose and unprotected by vegetation.
likely to occur in dry area where soil
is loose and unprotected by vegetation.
References
Birkeland, P. W. (2005): Soil and Geomorphology. New
York: Oxford University Press. Pp 52, 70.
York: Oxford University Press. Pp 52, 70.
Bunnet, R.B. and Okunrotifa,
P. O. (2003): Geography in Diagrams for West African 8th ed., Longman Group
Limited, pp 35, 63, 84.
P. O. (2003): Geography in Diagrams for West African 8th ed., Longman Group
Limited, pp 35, 63, 84.
Carla, W. (2008): Environmental Geology 5th ed, McGraw-Hill Inc.
USA pp 20-22.
USA pp 20-22.
Henderson, (2006): “Causes and Effects of
Soil Erosion” Omaff Fact Sheet Index 573.
Soil Erosion” Omaff Fact Sheet Index 573.
Morgan, R.P. (2006): Soil Erosion, London
Longman Group. Pp 22, 26, 71
Longman Group. Pp 22, 26, 71
Olatunji (2003): Health, Safety and
Environment, A conference Paper on EHOAN. Pp14-15.
Environment, A conference Paper on EHOAN. Pp14-15.