environmental risks of economic development Flashcards
soil erosion is the result of ….
it is largely related to….
the interaction of several natural physical processes and human activities it is having a negative effect on food production
it’s largely related to clearing the land and making it available for agricultural use
how is deforestation a major cause of soil erosion?
Deforestation - (clearing forests, woodlands and shrubland to obtain timber, fluewood and other products) this currently far in excess of the rate of natural re-growth
in rainforests areas deforestation occurs for logging for valuable timber, plantation agriculture, cattle ranching and construction of new settlements
bad effect on the habitat - species of plants/animals and destroyed the delicate food webs and food chains that exist in the natural environment
indigenous peoples homes have been lost
how is overcultivation a major cause of soil erosion?
because it’s when farmers are trying to increase the yield from their land so they aren’t letting it rest and recover - leaving the land fallow
the soil loses fertility as they are planting the same crop in the same land every year
how is rising populations a major cause of soil erosion?
rising populations are forcing farmers into farming more marginal areas (land that is of little agricultural or developmental value)
this can work in year when there is abundant rainfall but when the rains fail the crops fail and the soil quickly degrades
how is overgrazing a major cause of soil erosion?
when too many animals are kept on the same land for too long and the animals eat too much of the grass/plants to the point where they can’t re-grow
this is resulting in vegetation cover (percentage of plant-covered area to the total area of a given site)
and is a major cause of wind and water erosion
how is soil compaction a major cause of soil erosion?
this is when animals trample the ground, destroying the structure of the soil and leaving it open to wind and water erosion
what processes contribute to soil erosion
water and wind
water erosion - when water flows over the ground and removes parts of the soil - 60% of global soil erosion due to this
wind erosion - when dry soil particles are exposed to high winds and picked up
what processes contribute to soil erosion
over abstraction of ground water and salinisation and climate change
over abstraction of groundwater - soil drys out and is removed by wind/rain or resulting in lack of water in soil for germination
salinization - groundwater often contains a lot of dissolved salts, they are left on the surface of the soil when its evaporated. these salts build up and make the soil to toxic for farming
climate change - an increase in the number and severity of floods will cause more water erosion, also an increase in severity of droughts will cause more wind erosion
