water cycle case studies

Question 1

the Aswan Dam

Answer 1

in Egypt 90% of their source of water is from the River Nile
has led to flooding controls but has negative impacts of farming and coastal erosion
estimated that the lake has 20% losses of water due to evapotranspiration in the areas where the water is stationary and trapped by the dam and reserviour (10-16billion cubic meters)

Question 2

deforestation in the Amazon

Answer 2

a feedback mechanism
rainforests add water into the atmosphere due to transpiration and the moisture leds to the creation of precipitation
when rainforests are cut down less moisture goes into the atmosphere which can lead to a drought
loosing trees changes weather patterns due to the way trees take in moisture from the atmosphere and this will create a dryer ecosystem
rainforests create 50% of their own precipitation
they hold carbon but can switch from sink to source depending of severity of drought
drought kills the tallest trees first as they cannot pump water more than 100m from their roots which creates gaps in the canopy and leads to increased evaporation due to more sunlight

Question 3

Brazil 2014-2015 drought

Answer 3

worst drought for 80 years
high pressure systems blocked precipitation over Brazil and low pressure systems where forced elsewhere
water levels in river dropped so low people in industry and agriculture started abstracting groundwater
25,000 people applied for a liscence to dig a well to get water but this only accounted for around 30% of well that where dug
2.5 million boreholes where illegally created
overpopulation was the main isssue

Question 4

Australia drought

Answer 4

2019
positive indian ocean dipole meaning the eastern waters in the indian ocean become cooler and the western waters become warmer so atmospheric moisture over Australia decreased cutting off Australias key rainfall season
major bushfires increased temperatures and prolongued the drought
1/3 of the water consumed is groundwater
water is being abstracted faster than it is replenished due to commercial uses and population increase

Question 5

cumbria floods

Answer 5

314.3mm rain fell in 24hours in 2015
bare and dry soils, impermeable areas and faster runoff means precipitation reaches floodplains quicker
deforestation for agricultural reasons
storm Desmond and strom Eva cost £5.8bn across the UK
Keswick = debris and damage shut off the A591, lack of vegetation and steep slopes funneled water downwards, 2009 flood defences could.t cope
York = ‘The Foss barrier’ was lowered to protect York but this led to 600 homes being flooded elsewhere

Question 6

internal water conflict in spain

Answer 6

5000 people live in a small village in central spain

Question 7

international water conflict with turkey, syria and iraq

Answer 7

• the ‘Basra Province’ is the most important area and water source in Iraq and the ‘Shatt Al Ahrab’ is the most important water source in the middle east
• the Euphrates and Tigris are Iraqs main water sources but they’re not controlled by Iraq and the sources begin in turkey and syria
• 81% of iraqs water is controlled by its neighbours
• due to the creation of 22 dams and 19 hydropower plants in turkey across the Euphrates-Tigris basin (to keep water in their country), the Euphrates river has decreased in water flow into iraq and syria by 80% = this means water is highly polluted and sparce
• wars in iraq have led to 4 hydroelectric dams being destroyed meaning their water cannot be cleaned
• the uprising of ISIS in the North of iraq meant that water was weaponised and 100,000 people where forces to flee the South of Iraq as they had insufficient supplies of clean water
• questioning into the corruption of governments and their lack of investment into water treatment has led to riots in iraq
• low flow rates in iraq have led to salt water encroachment by 150km inland
• tensions between these countries remain high

Question 8

international water conflicts between India and Pakistan

Answer 8

• The river and its five tributaries together make up the Indus Basin, which spans four countries and supports 215m people.
• fast-growing populations and increasing demand for hydropower in each country means the Indus is coming under intense pressure.
• India and Pakistan, the two main countries in the basin, divided up rights to the various tributaries under the ‘Indus Water Treaty of 1960’
• India is building several major dams along the Chenab, a tributary of the Indus that was originally allotted to Pakistan under the IWT.
• global warming will raise the sea level and make Himalayan glaciers (which is the ultimate source of the Indus) melt ever faster. Flooding is expected to become more frequent and more severe, nationalist media in Pakistan have blamed floods in the country on poor water management in India.
• Climate change is also expected to affect monsoon patterns in South Asia, and could result in less rainfall for India and Pakistan. This could be disastrous as summer monsoon rainfall provides 90% of India’s total water supply.
• there is no institutional framework or legal agreement for addressing modern issues such as the effects of climate change on water availability in the Indus Basin. The 1960 treaty does not have any clause to deal with transboundary aquifers, and there are no agreed rules for the allocation and management of shared groundwater.
• a groundwater aquifer helps support the huge population in the Indus region but far more water is being taken out each year than is replenished by rain.
• Around 90% of Pakistan’s food and 65% of its employment depend on farming and animal husbandry, which are sustained by the Indus Its floodplain, where most of Pakistan’s population live, is one of the largest agricultural regions in Asia.
• Fears of future water shortages due to the construction of dams are causing diplomatic tensions between India and Pakistan
• Pakistanis also fear that India will use its upstream dams to control how much water flows down into Pakistan via the Indus.