Human impacts on the water cycle Flashcards
deforestation causes:
Less interception and less transpiration
how does deforestation lead to less interception and what impacts does this cause?
Removing trees means that less water is intercepted by leaves. this can increase the leaching of nutrients into the soil. It can also increase surface runoff which will wash away soil.
How does deforestation lead to less transpiration and what impacts does this cause?
Trees evaporate moisture back into the atmosphere to form clouds, without them there can be droughts inland
Urbanisation causes:
Less infiltration, more surface runoff and evaporation.
How does urbanisation lead to less infiltration and what impacts does this cause?
Vegatation is removed and replaced by impermeable surfaces like roofs, roads and tarmac. Water therefore can not travel through the soil, reducing percolation, and therefore lowering the water table.
How does urbanisation lead to more surface runoff and what impacts does this cause?
Water flows over the impermeable surfaces and collects in drains this can lead to higher river levels.
How does urbanisation lead to more evaporation and what impacts does this cause?
Increase in impermeable surfaces leads to more surface water evaporating and less percolating through the ground.
Irrigation causes:
Reduced river flow, increase in evaporations-transpiration and evaporation.
How does irrigation lead to reduced river flow and what impacts does this cause?
Farms take water from the river or ground water storage, reducing river flow.
How does irrigation lead to increased evaporations-transpiration and evaporation and what impacts does this cause?
Planting crops can increase evaporations-transpiration and evaporation by having more water in surface stores like canals and ditches. This lowers the water tables.
What happens as crops grow?
More water is removed from the water cycle.
Dams and reservoirs cause:
More water storage and evaporation, less surface runoff and less water being transferred downstream.
How do dams and reservoirs lead to more water storage and evaporation and what impacts does this cause?
Water infiltrates into the water table level and raises the water table underground . This can result in more clouds forming and effect rainfall patterns.
Mining and quarrying causes:
Increased surface runoff, increased evaporation and decrease in ground water storage.
How does mining and quarrying lead to increased surface run off and what impacts does this cause?
vegetation is removed.
