Hydrological cycle - Case studies

Question 1

El Nino 1997/98

Answer 1

• 1997-1998 the biggest El Nino in recorded history
• 2100 Deaths
• $33 billion in damages
• US received major weather events (tornadoes, hurricanes)
• Categorised by very hot temperatures in America, Australia and South East Asia

Question 2

El Nino 2015

Answer 2

-6 million tonnes of imported crops in South Africa
In Africa, the rainfall season was 50 days late
-150 million had to leave due to flooding in Latin America
-£68 million was requested by the WHO for the 7 worst affected countries in order to contain health risks
-22 Million east Africans were threatened with acute malnourishment

Question 3

Forest Ecosystems- South West USA- Drought

Answer 3

• Between 2000-2003 a combination of severe drought and unusually high temperatures led to a die off of the Pinon Pines species
• heavily susceptible to pine bark beetle attacks, in some areas more than 90% of them died
• forests store 0.73 tonnes of carbon per hectare each year, important for regulating climate change.

Question 4

Storm Desmond

Answer 4

-Hit Cumbria in December 2015
-prolonged and heavy rainfall through a mechanism known as a warm conveyor
-5200 homes were flooded
61,000 homes lost power as an electrical substation was flooded
-405mm of rainfall at Thilmere in 38 hours
-major railroads were disrupted

Question 5

Everglades and Kilimanjaro, climate change is destroying world wonders- The Guardian

Answer 5

• IUCN, (International Union for Conservation of Nature), world heritage sites at risk from damage due to global warming has doubled to 62 in the past 3 years.
• Coral reefs in the Seychelles are badly affected by ocean temperatures
• Australia has 10 natural heritage sites where climate change is at high or very high risk.
• Destruction can be overcome, elephant and chimpanzee population in Ivory Coast have recovered due to better management and international support.

Question 6

Congos basin peaty swamps are new front in climate change battle. - The Guardian

Answer 6

• peat sequesters carbon and slows down global warming
• peatlands in congo contains 1/3 of hte worlds tropical peat
• 56,000 sq miles, an area larger than england
• African peatland contains over 30 billion tonnes of carbon accumulated over 10,000 years, equivalent to 3 years of the worlds fossil fuel emissions.
• two months of intense fire in Indonesia released an estimated 884 million tonnes of co2

Question 7

Pacific Islands could lose 80% of their fish because of climate change - The Independent

Answer 7

• local extinction of marine species exceeded 50% of current biodiversity levels, at times reached 80%
• Pacific islanders rely on them for protein and economic oppurtunities
• change relies on the actions of all countries to materialise their commitment to limit greenhouse gases.

Question 8

Climate Change is turbocharging the growth of trees in cities - and it could help reduce storm water flooding

Answer 8

• urban and rural trees have undergone accelerated growth since the 1960s
• urban trees are growing faster than rural trees due to the urban heat island effect- this involves higher temperatures in cities compared to the surrounding landscapes, this may stimulate photosynthesis and help plants to grow
• sequesters more carbon and provides moe ecosystem services such as reduced storm water run-off
• air pollution reduction and storm water run off
• more rapid tree ageing and earlier replacement and replanting.

Question 9

Cape Town- Drought

Answer 9

• they want residents to save water but they’re not
• 36.8% down
• Saving 20 million litres of water a day
• 82 million litres above 500 million litre target
• looked at strategic planning- city will fund 7 water projects desalination plants, aquifer projects, water recycling
• The same physical factors that encourage drought conditions can also lead to water scarcity in countries
• Mayor Patricia de Lille
• 51 % of Cape Townians put tremendous effort into saving water.
• significant progress but still a long way to go

Question 10

The Ogollalla Aquifer

Answer 10

• largest body of water in mainland America
• it used to have a depth of 240 feet but now it only has a depth of 80 feet
• Farmers in Happy are completely running out of water
• Many Farmers are having to hand over their land to the governments conservation programme in exchange for grants

Question 11

Water Usage Facts

Answer 11

• McKinsey and Company by 2040 water demand will be 40% greater than todays accessible and environmentally sustainable supply
• 71% of total water supply today goes towards irrigating our food.
• subsidies given to farmers which need an excessive amount of water.
• Subsidies are also handed out to turn food into fuel, this means that food costs go up and also wastes precious water resources

Question 12

The Mekong River

Answer 12

• There is a dam (Xayaburi Dam, Laos)
• 40 Dams in the upper course
• It flows through 7 countries
• The mouth of the Mekong is in Laos
• home to 1200 fish species
• 2 million people rely on fishing in Cambodia from the Mekong.
• 70% of the protein diet of people is fish
• 70% of the entire diet is rice in areas surrounding the Mekong, difficult to grow

Question 13

The Mekong, Economist

Answer 13

• According to NGOs 20 million have been moved/displaced due to dams being created.
• In 2014, lower Mekong countries produced more than 100 million tonnes of rice, 15% of the worlds supply.
• 20,000 plant species and nearly 250 animal species
• 282 Gigawatts of hydroelectric capacity has been produced in 2014.
• The 11 dams proposed in Laos and Cambodia could block migration of around 70% of the Mekongs commercial fish catch.
• In the lower basin of the Mekong the average persion eats 60kg of freshwater fish per year which is more than 18 times what is on the Menu in Europe and America

Question 14

The Mekong, Economist Continued

Answer 14

• The 3.5 billion dollar Xiayburi Dam
• Laos wants hydropower to be its main source of revenue by 2025, The thai have agreed to buy 95% of it.
• Power demand in the region is expected to double between now and 2025.
• The Mekong River Comission estimates that the Mekong yields around 2.6 million tonnes of wild fish per year, 2 billion dollars in dockside sales
• Mekong fisheries are estimated to be 5 to 9.4 billion dollars.
• Mekongs Delta is home to 18.6 million people, 1/5 of Vietnams population, 3/4 work in agriculture.
• Up to 70 % of the deltas agriculture land could be subject to saline intrusion.

Question 15

Water Transfer Projects- China’s South-North Water Transfer

Answer 15

• North China is suffering from water scarcity and the problem is most severe in the Hoi basin.
• 1/2 of Chinas people and 2/3 of the farmland are in the north.
• 80% of the water supply is in the south (Yangtze River Basin.)
• The water table of of Beijing has fallen 300m since 1970.
• 60% of the river is poor quality as a result of pollution
• China has designed the largest water transfer scheme in the world.
• Has the capacity to deliver 25 million m3 of freshwater from the Yangtze River
• many farmers claim that the water will be too expensive and therefore their only option is to exploit groundwater.
• more than 300,000 were displaced during the construction of the central route.

Question 16

Ethiopias Gibel Gibe Dam

Answer 16

-It is owned by the Ethiopian Electric Power Corporation.
-when it was commissioned it was the 3rd largest hydroelectric plant in Africa.
-It will make Ethiopia 95% dependent on hydroelectric power.
-The electricity power output is expected to brin about 407 million a year.
-it also provides flood protection
NEGATIVES
-Terri Hathaway, International Rivers Director “the river will condemn half a million people to hunger and conflict”
-200,000 people rely on the Omo River, many with chronic hunger, will worsen with the dam.
-May cause 290km of forest to die out

Question 17

Tampa Bay Desalinisation plant

Answer 17

-It will provide up to 25 million gallons of drinking water per day to the region.
-the freshwater will be seperated from seawater using reverse osmosis.
-The Tampa Bay plant collects up to 44 million gallons of seawater a day
STRENGTHS
-The water quality is safe- it is not dangerous or hazardous to any living thing.
WEAKNESSES
-Chemical waste in the environment
-initial start up costs are high.

Question 18

Singapore - Managing water the ‘soft way’

Answer 18

• Population of 5.3 million
• relied on Malaysia for water supply
• Aware of the risks of being dependent on another country.
• Water reclamation plant which is capable of treating 320 olympic sized swimming pools of water a day
• Demand is now 45% domestic, 55% non-domestic
• Demand in 2060- 30% domestic, 70% non-domestic
• Singapores per capita household water consumption has reduced from 165 litres a day in 2003 to 148 litres in 2016.
• The Active, Beautiful,Clean Water Programme
• optimises bodies of water to create pockets of community space to allow a whole range of activities to enjoy.
• 100 locations are indentified for the implementation of this programme by 2030.

Question 19

The Colorado River

Answer 19

• It is a river that used to run into the pacific ocean
• now that the water fills pools and fountains in Vegas, irrigates crops and provides drinking water, there is nothing left to make it to the ocean
• 2330km long through a basin through 637, 000km2
• 29 dams and a number of diversion projects exist
• 1990 the US used their full allocation for the first time making the issue worse
• Nevada has tried negotiating for extra water allocation
• California has introduced irrigation restrictions and is investigating desalination
• Arizona has established a water banking authority 1996
• provides drinking water for 36 million people
• Passes through 11 national parks and monuments
• Fuels a $1.4 trillion annual economy
• Climate change is expected to further reduce the rivers flow by 10 to 30 percent by 2050.

Question 20

Everglades- Wetland Ecosystem

Answer 20

• Located in Florida
• wetland ecosystem (on tropics of land naturally dries in any season, tropic of cancer)
• Wildfires occur from drought
• limited velocity
• convectional rainfall around tropics, high temperatures cause storms.
• lightning strikes any vegetation which catches fire

POSITIVES

• Fires good for everglades as fires are a natural positive for an equilibrium, vegetation renews itself.
• nutrients of vegetation is released from vegetation through burning into soil
• most biotic creates have adapted

NEGATIVES

• invasive species (not adaptable)- end up in areas they don’t live in, migrate (fish)
• period of drought- less water input
• functioning and breakdown of bacteria is less
• less outputs
• water facilitates breakdown of nutrients
• hydrophylitic plants are affected.
• less water river and groundwater flow into wetland leads to open water shrinking and drying up, leading to habitat loss
• less able to provide clean water for streams