Lecture 5 Flashcards
Soil erosion occurs due to transport of ……
wind, water or ice
Two of the most important agents of erosion in many counties including Ghana is…
water and wind
Why concern with erosion?
the topsoil is the part of the land with the highest organic matter and as erosion removes the top soil, it heavily impacts the agricultural land
What is rainsplash erosion?
the detachment of small soil particles by the direct impact of raindrops.
Splash erosion is only effective when rain……
falls with high intensity
The removal of soil particles by water flowing overland as a sheet is called
Sheet erosion
The removal of soil particles by means of runoff in small channels is called
Rill Erosion
The removal of soil particles by means of run off in gullies (larger channels) is called
Gully erosion
The most important climatic factors that control soil erosion by water are
rainfall intensity and frequency
The magnitude of soil erosion tends to be higher in soils with …….. structure
poor
Soils with faster ……. have a greater ability to resist erosion
infiltration rates
Organic matter protects the soil by absorbing the impact of raindrops. hence oils with greater organic content are able to ……….. erosion.
resist
Past erosion strongly affects a soil’s
erodibility
Exposed sub soils (B horizon) on previously eroded sits are generally more ……… to erosion than surface soils.
prone
Vegetative cover protects the soil from erosion. True or false?
True
The steeper the slope of a land surface, the ……….. the speed of surface runoff
greater
The magnitude of soil erosion by water ……… as the slope length increases.
increases
Humans play a major role in soil erosion through…..
deforestation, grazing, housing construction, mining among others.
What is deflation?
it occurs when wind causes small particles to be lifted and moved to another place.
As suspended particles are moved, they may erode the surface of solid object by a process called
Abrasion
Soil erosion by wind also tends to be more severe at areas with no ……….
windbreaks
The UNEFP-funded GLASOD project which was coordinated by ISRIC provided a first world map of human-induced soil degradation in …..
1990
full meaning of GLASOD?
Global Assessment of Human-induced Soil Degradation
Cultivation along steep slopes can cause soil erosion true?
Yes
one of the major causes of soil erosion in many parts of the world is
deforestation
The most serious off site effect of soil erosion is the…..
movement of sediments into water courses
What does siltation do?
it alters the habitat of aquatic organisms
Soil erosion is one of the major causes of water pollution. True?
yes
Drinking and eating a lot of nitrates can
stop red blood cells from doing their job of carrying oxygen.
The most common cause of baby blue syndrome is
water contaminated with nitrates
