desertification Flashcards
erosion
the wearing away and removal of material by a moving force, such as water
desertification
the spread of dessert conditions into what were previously semi-arid areas
arid
dry
why are arid regions at more risk of desertification?
there is less rainfall and so the land is not suitable for plants to grow
in the Sahel, what months can you expect little to no rainfall?
(when is the dry season?)
June through to January
where can you expect less wildlife in the Sahel and why?
on the drier desert edges because they are inhabitable
name 2 causes of desertification
climate change, human activity
what is a possible cause for desertification in the Sahel?
Human activity. in the 1960’s, there was an increase in population so more trees were felled. This quickly lead to over cultivation and overgrazing. Without humus the soil was able to hold little to no water and so was eroded by the wind.
overgrazing
a situation in which there are too many animals eating grass in an area, which damages the environment
pasture
field
vegetation cover
the percentage of soil which is covered by green vegetation.
over-cultivation
ongoing agriculture depletes the soil’s nutrients and degrades the overall health and fertility of the soil
humus
the organic component of soil
Why do you think people would migrate out of the Sahel?
People would want to out of arid areas because there is little vegetation, livestock and water making it hard to survive.
name soil management techniques
crop rotation, planting trees, ‘magic stone’
explain how an increase in population can lead to soil erosion
- increase in demand for recourses
- deforestation, overgrazing, over-cultivation
- soil has less protection from the weather
- loose top soil is blown away
grazing
grassland suitable for pasturage
afforestation
replanting trees
logging
the activity or business of felling trees and cutting and preparing the timber
reforestation
the process of replanting an area with trees
biomimicry
technology is manufactured to imitate the living
afforestation
the process of planting large numbers of trees on land which has few or no trees on it
why is emerging deforestation tech sustainable?
technology is becoming more and more innovative, soon enough new ideas will catch on and become standard
why might people cut down trees in the rainforest? Name 6 reasons.
- commercial logging
- road building
- land for farmers
- land for architecture
- mining
- HEP (hydro electric power)
some developing countries encourage the clearance of forests. Why?
- the revenue earned can pay of economic debts.
2. fast growing populations (Brazil and Malaysia) need more land is needed for housing and farming
a natural cause of desertification
climate change
explain how less rainfall can lead to desertification
- less rainfall means bare soil therefore an increased water-flow overland that washes the soil away.
- Water is drained from the soil so The water table is lowered so few plants grow. and soil blown away more easily and a dust bowl is created.
population growth and desertification
rapid population increase puts more pressure on the land to grow more food
migration and desertification
as desertification takes hold in one area, local people migrate elsewhere in search for food and water, Unfortunately, wherever they settle, they increase the population pressure on the environment
overgrazing and desertification
too many goats, sheep and cattle can destroy vegetation
over-cultivation and desertification
land becomes exhausted and crops will not grow
deforestation and desertification
the roots no longer bind the soil
