Case Studies Paper 1 (Hazards and Freshwater) Flashcards
(16 cards)
One internationally shared water resource and the role of different stakeholders GERD
Grand Ethiopian Renaissance Dam:
145m tall, 1600m+ and 14km east of 🇸🇩. Cost $5billion, can generate 16,000 gigawatts/year and will double 🇪🇹 electricity generating capacity increasing supply to households from 20% to 70%.
More electricity generated than is required so 🇸🇩 can buy at affordable price w/ 🇸🇩 buying 1000 gigawatts whihc is 5x amount they’re currently buying from 🇪🇹, boosting 🇪🇹 economy and dam will allow for irriagtion and by 2060, GDP of 🇪🇹 increases by £66billion.
However, 🇪🇬 not happy as could cause drought as 90% of 🇪🇬 freshwater comes from nile and would cause crop failure and electricity shortages as less water through the Aswan High Dam. A decreases of 2% of nile water causes 200,000 acres of irrigated land to be lost and 🇪🇬 describes the GERD as an existential threat
One internationally shared water resource and the role of different stakeholders Aswan High Dam
111m tall and 22 miles long
Cost $1 billion in 1970 = $8billion in 2025 and funded by soviets. Displaced 50,000 and flooded artefacts. Took 6 years to build and fill so temporary water reduction. 10% of water was lost in construction and water is lost via evaporation
Generates 10 billion kwh/year and increased agricultural capacity of 🇪🇬 and protects from droughts and flooding. Good fishing industry in lake Nasser behind dam as recreational and commercial fishing for the Nile Perch and high tourism to the site. Employed 34,000 during building and multiplier effect caused 🇪🇬 GNI to increase by 4.9 million egyptian pounds. Reservoir also used for textile industry
2 contrasting detailed examples of flood mitigation of drainage basins
Mississippi River - 3800km lomng and most recent flood killed 50 and dealt $12 billion in damages
To mitigate floods:
The Mat sinking unit (US army corps of engineers) built concrete matts onto natural levees and impermeable concrete walls to decrease erosion damage.
Army corp built 20 major flood control reservoirs in upper course. If rain expected, release some of the reservoir to prepare.
In urban areas concrete walls, flood gates, drainage basins, dredging and pumping stations
LANDSAT satelite imagery to access damage and establish areas prone to flooding aiding future planning
Federal Emergency Management Agency’s (FEMA) flood insurance program that states if damage to a home exceeds 50%, not rebuilt
Jakarta, Indonesia
Faces significant flooding due to rapid urbanisation and many parts of the city are below sea level and half the city is sinking at rate of 9 inches/year
On 1/1/20 400+mm rain and ciliwung and cisadane rivers flooded killing 66, displacing 60,000 and some parts of the city were 2 metres under water
Cloud seeding planes were used ti increase rainfall over oceans instead of over land to reduce flooding
Since to mitigate risk:
Widened and deepened flood channels, built the east flood canal, started Jakarta emergency dredging initiative to increase river capacity, created more green urban spaces to decrease surface run off, created advanced warning system and educated poorer communities using community workshops to explain how to protect themselves during flooding and prepared life-vests and emergency kits.
Examples to state the role of stakeholders of the consequences of agricultural pollution
Agriculture leads to the degradation of water sources affecting all stakeholders.
Texas has largest cattle population in the US, w/ around 13 million animals. Feedlots lead to mass eutrophication as the nitrates from the manure leeches into water sources causing contamination. Also, agriculture accounts for large percentage water use of a country (e.g 11% of french water extraction of freshwater down to agriculture and greatly increases in the summer) so pressure on water companies who need to supply clean water to consumers and domestic consumers that rely on clean water supplies. Mass eutrophication occurred in Lake Dianchi as pig farming in the Yunnan province of China and has lead to destruction of habitats and marine ecosystems due to harmful algal blooms
Salinisation frequent in farming due to irrigation of crops which leads to loss of aquifer capacity, has reduced Texas water table by 50m and has reduced world’s albedo effect by 10% as replaced sandy surfaces with dark green. Salinisation occured in Aral sea in Kazakhstan and Uzbekistan as Soviets in ’60s diverted 2 rivers for irrigation causing the lake to lose 92% of its volume and salinity increased fro 1% to 22% making water uninhabitable and caused 40,000 unemployed from the fishing and camel industry. Also, created toxic winds that cause respiratory illnesses and fertilisers are spread by wind.
How does Bangladesh mitigate flooding?
In Bangladesh the Flood Action Plan was created after the devastating floods in ‘87 and ‘88. Had heavy favouring of structural mitigation and had several dams planned but most were not finished due to funding issues. Implemented compartmentalisation in Tangail, spanning 13,305 hectares as embankments were made to act as erosion control measures.
This is just to be aware of- better studies are the Mississippi and Jakarta examples
What is an example of local action cases for water management features?
Cape town suffered severe drought from 2015 to 2018 and the city suffered severe water shortages. The city government implemented water restrictions, including bans on outdoor and non-essential water use and towards the end limited water per capita to 13 gallons per day. Public were educated and responded positively and effectively and the city implemented strategies like wastewater to potable water filtration and due to innovative solutions, the day zero (day were municipal water supplies would be turned off) was averted as rain came in June so the dam levels recovered and by September 2018 city began to ease water restrictions.
Earthquake hazard events of similar magnitudes but with contrasting human impacts- Haiti
Haiti lies on a conservative boundary between the north-american plate and the caribbean plate along the Enriquillo-Plantain Garden fault zone. In 2010, EQ of 7 on richter scale, 25km west of capital, Port-au-Prince, at depth of 13km below surface. Aftershocks as strong as 5.9 and only 9km below surface. 1/3 of population affected and required emergency aid according to Red cross w/ 230,000+ killed and 250,000+ injured and 1 million+ left homeless. This was due to poorly constructed buildings, shanty settlements being overcrowded, many of Port-au-Princes 2 million residents lived in tin roofed shacks on side of steep ravines and Haiti being one the poorest countries in the world. EQ degraded an already feeble healthcare service, destroying many hospitals and clinics. and 216,000 infected by cholera and looting frequent so 50 looters were arrested to maintain order. UK donated £23 millions and 6 international and 8 Haitian medical teams based in mobile clinics. Haiti needs to long term strategy for rebuild but has been affected by political instability, as president was assassinated, gang violnece and the location along plate boundary means EQs are common leading to further set backs.
Earthquake hazard events of similar magnitudes but with contrasting human impacts- Christchurch
Lies on conservative boundary between pacific plate and australian plate. EQ w/ 7.1 on richter scale at 4.35 am 4/9/2010. Aftershocks continued until 2012, strongest of which was 6.3 in 2011. Lack of casualties compared to Haiti as happened in early hours on morning so many in bed in timber-framed homes and the building regulations in NZ are very high. The 2011 aftershock killed 183 and hit the region 22/2/2011 and despite it being smaller it was more deadly since:
Epicentre was closer to christchurch
EQ focus was shallower at 5km compared to 10km in 2010
Occurred at lunch when business district was more busy
Buildings had already been weakened by previous EQ and then collapsed e.g CTV building collapse which accounted for 60% of death toll of EQ
Liquefaction significantly greater causing upwelling of 400,000 tonnes of silt.
Volcanic hazard event in contrasting plate boundary locations- Montserrat
Small British oversea territory in Caribbean and in July 1995 the 400 year dormant Soufriere Hills volcano erupted. Volcano was formed due to the subduction of the South American and North American plates under the Caribbean plate.
At first the volcano expelled steam and ash and the capital, Plymouth, w/ pop of 4000 was covered in ash and abandoned. Plymouth contained all government buildings and most shops and services. Southern third of the island was evacuated and all public services (government, healthcare and education) was moved to northern part of the island and Montserrat’s population fell from 11,000 to 4,500 with many fleeing to nearby Antigua but some of those displaced stayed living in tents. There is still an exclusion zone present for the entirety of the southern part of the island and only allowed for scientific research.
Volcanic hazard event in contrasting plate boundary locations- La palma
Cumbre Viejo erupted 19/9/21-Dec 21 at a volcanic eruption index of 2 or 3 and it’s a cinder volcano. La Palma isn’t located on a boundary and the volcano formed due to a hotspot. 1500 houses destroyed in lava flow and 1500+ of other buildings e.g churches, schools, shops destroyed. Lave flow covered 1000 hectares and water supply was cut to 3000+ people. 400 hectares of banana farms destroyed and only 1 death. Over 1000 people were evacuated after the eruption of 19/9/21 and further 5600 evacuated over following weeks. Deaths and injuries were minimised due to La Palma’s ‘Local Hazard Mitigation Plan’ which reduced impact of hazard event as people are encouraged to have an emeregency kit ready and insurance cover means that recovery post evenet is more rapid. La plama also has well trained and equipped emergency services.
Volcanic hazard event in contrasting plate boundary locations- Indonesia
Mount Merapi in Indonesia erupted 25/10-30/11 2010 at a VEI of 4. Located along a destructive plate boundary where Indo-Australian plate is subducting below eurasian plate and the composite volcano is part of the pacific ring of fire. Eruption killed 353 and ;lead to respiratory illness and skin irritation due to significant release of SO2. Damage to 19000 homes and displaced 350,000. Almost 1/2 of those affected by eruption suffered mental health issues and the eruption caused disruption to healthcare and education and religious practices. Indonesia lost £450 million due to impact predominantly on farming and tourism with 2500 flights cancelled and international tourism decreased by 70%. 30 bridges were damaged and food prices increased due to destruction of crops. Dramatic loss in biodiversity and habitats w/ 200+ hectares of forest destroyed. Acid rain damaged ecosystems and long-term pollution of land and rivers. Social unrest w/ looting and political instability and conflicts over government response and food shortages. High deaths, injuries + displacements as people refused to leave homes due to cultural beliefs, caring for elderly relatives, caring for livestock + inertia where they didn’t want to leave. Population density also increased and local people didn’t believe scientific monitoring is accurate and communication regarding danger of eruption was slow and ineffective.
Mass movement event with contrasting physical characteristics - Venezuela
In Vargas State 15-16/12/99 rainfall of 40-50% above usual and triggered fast moving debris flow down steep mountains and canyons and mud and landslides across the region. Debris flow included boulders up to 10 metres tall and the flow peaked at 14.5 metres/second. The range of deaths is large with possibly up to 50,000 as many people were never found and whole families were buried by mudslides and swept to sea. 150,000+ homeless and towns e.g Cerro Grande were completely buried. Up to 10% of the population of Vargas state died and 70% were affected. Crops were destroyed, seaport Maiquet hit leading to hazardous material leaking from contained and economic damage was $3.5 billion. Looting occurred so martial law had to be implemented. Disaster was so deadly due to high population density in coastal areas, poor building quality as many areas affected were squatter settlements, corruption amongst government officials allowing homes to be built in vulnerable areas, in 1999 government stopped collecting rainfall information so there was a lack of warning so no evacuation orders were issued and state government ignored report from Civil Defence Agency urging them to declare state of emergency 12 hours prior to main debris flows.
Mass movement event with contrasting physical characteristics - Italy
In Ponzano Feb 2017 slow moving landslide of 1 metre per day occurred due to combined effect of EQs and snow melt causing the soil to saturate and there was rainfall of 81mm in 4 days. Estimated 7 million m3 of material moved and over 100 people evacuated from 35 houses and several buildings collapsed. Agricultural land around the village became unsafe. No deaths due to low pop density, slow movement enabled efficient evacuation, landslide monitored by Civil Protection Department and emergency services supported people to recover property from evacuated buildings.
Contemporary dam building in one major drainage basin- China
I don’t know it the GERD also fits this but spillett put it separately on the document so it’s been made
Three Gorges Dam
Worlds longest dam on Yangtze River and lake behind is 600km long.
Advantages:
Generates 18,000 megawatts, 8xAswan, reducing China’s dependency on coal, supplies energy to Shanghai and Chongqing, protects 10 million form flooding w/ 300,000 peoples dying as a result of flooding in 20th century. Has allowed shipping in lake behind as raised water levels by 90m and turned rapids into a lake. Generated thousands of jobs both in construction and industrial development associated w/ availability of cheap energy
Disadvantages:
!.2 million displaced for dam with dozens of towns with populations 100,000+ flooded and much of the land available for resettlement in 800m above sea level so has less fertile land and is colder. To reduce silt load afforestation needed but resettlement of people is increasing pressure on the slopes above the dam. 530 million tonnes of silt carried through gorge annually and may cause the port at the head of the lake to become silted up and cause a delta to develop, most floods in recent years have come from rivers that join the Yangtze below the dam, region is seismically active and landslides are frequent so the additional weight of the water is adding to the activity, cost $70 billion and archaeological treasures were drowned including zhang fei temple and the dam has disrupted aquatic ecosystems with the Yangtze river dolphin being believed as extinct.
Changing river management and future possibilities for a wetland area- Kissimmee
In 1960s, the kissimmee river was channelised into 90km, 10m-deep C-38 drainage channel to protect from flooding after seasonal rainfall had caused mass floods. Caused anoxia as water moved to quickly, waterfowl and wading birds decreased by 90% and up to 14,000 hectares of wetlands lost. 1999 tried to restore river by back filling 22 miles of c-28 canal and reconstructed 10 miles of river channels and 40 miles have been restored.
Restoration cost $410+ million and restoration may cause higher losses of water due to evapotranspiration during wet periods.
Dissolved oxygen levels have doubled, making survival of aquatic species much higher, 8 shorebird species returned and so have ducks. Created over 11,000 hectares of wetlands once again and poses some possible financial gain as increased recreational use for fishing and hunting and ecotourism could enhance local and regional economies.
The Ramsar Convention, is an international treaty that promotes the conservation and wise use of wetlands and their resources. It was signed in Ramsar, Iran, in 1971 and came into force in 1975. The convention’s key activities include designating wetlands of international importance as Ramsar Sites, promoting wise use of all wetlands, and fostering international cooperation for wetland conservation. In operation on the kissimmee
One IDBM plan-Europe
The danube, Europe’s 2nd longest river and has the International Commission for the protection of the Danube River (ICPDR) which was established in 1998 when the Danube River Protection Convention (DRPC) came into force
The ICPDR focuses on water quality, risks from accidents, monitoring and information management, river basin management and implementing EU water framework directive. Lower basin countries established the Lower Danube Green Corridor which is 400,000 hectares of protected wetland and 100,000 hectares of new wetland. This has increased capacity of Danube to reduce pollution, purify water, retain floodwaters, support fisheries and tourism and provide new habitats. Danube as result of ICPDR has high biodiversity, well known for lakes, wetlands, floodplain forests and meadows and provides spawning ground for fish. Also source of drinking water for 20 million and economically important for industry, mining, farming and energy production. Over 80% of original floodplain was lost due to construction projects, river erosion, pollution from industry etc and management made hard as in 17 countries with some of them used to be soviet. Post collapse of USSR management much easier.
