Lesson 3 - Human disruption to the drainage basin Flashcards
What human disruptions are they to the drainage basin? (6)
farming deforestation abstraction dams/defences pollution overpopulation/urbanisation
How does groundwater influence the drainage basin?
Water taken from aquifers faster than is replenished which causes reduced ground water flow and a lower water table. Industry/deforestation can increase groundwater storage increasing flooding if the water table reaches the surface
How is groundwater influencing the drainage basin in China?
In China groundwater supplies 40% of farmland and provides 70% of drinking water but ground water dropped by 1 meter from 1974-2000
How does dam construction influence the drainage basin?
Increases water surface stores and evaporation which reduce downstream river flow and discharge.
How does dam construction influence the drainage basin in Egypt?
Lake Nasser behind the Aswan Dam in Egypt is estimated to have evaporation losses of 10-16 billion cubic metres every year. A loss of 20-30% of Egypt water volume.
How does urbanisation influence the drainage basin?
Building creates impermeable surfaces that reduce infiltration and increase surface runoff and through flow through artificial drains. Often increases river discharge as a result.
How does urbanisation influence the drainage basin in the UK?
increased flooding in Maidenhead (2014), York (2015) and Manchester (2015).
What is cloud seeding?
is the attempt to change the amount or type of precipitation by dispersing substances into the air that serve as cloud condensation nuclei.
How does urbanisation influence the drainage basin?
New technology and research claims to have produced reliable results that make cloud seeing a dependable and affordable water-supply practice for many regions, but its effectiveness is still debated.
How does urbanisation influence the drainage basin in China and the USA?
China used cloud seeding in Beijing just before the 2008 Olympic Games to create rain to clear the air of pollution.
It is used in the Alpine Meadows ski area in California to improve snow cover, and was used in 2015 in Texas to reduce the impact of drought.
How does deforestation influence the drainage basin?
Reduces interception and evapotranspiration which increases infiltration and results in saturated capacity quickly. Soil erosion can happen as of a lot of rain fall travelling overland with out plants to bind soil in place
What is the case study for deforestation in influencing the drainage basin?
Amazonia
How does agriculture influence the drainage basin?
Pastoral farming compacts the soil by live stock and increases overland flow.
Arable farming increases infiltration by loosing the soil
How does mining influence the drainage basin?
Reduced vegetation as its removed, increased surface run off. Silting up of lakes leads to reduced storage
