WATER CASE STUDIES Flashcards
What caused the 2014-15 brazil drought?
Usually, rainfall in brazil comes from the south Atlantic across the brazil basin but in 2014/15 a series of high-pressure systems diverted them north resulting in dry air for Brazil and heavy rain in bolivia.
What were the impacts of the 2014/15 drought?
> Said to be brazils worst drought: water rationing for 4 million people; water supplies cut off for 3 days a week in some towns.
Halted HEP production causing power cuts.
Dangerously low levels of reservoirs (some down to 1%) and depletion of aquifers
coffee bean reduced so prices pushed up to 50% globally.
What were the human actions as a response to the drought?
Farmers and industries increasingly used groundwater as rivers had low levels of water. This became the only water source for many urban poor and remote rural areas.
>due to the high fees of 3000$ to have a license and the high expenses of running a well 35K- 100K in $ many people instead opted for illegal wells, shrinking groundwater levels.
>Illegal wells were shallower and less filtered by bedrock containing industrial polutants and higher levels of bacteria.
What were the impacts of drought on rainforest ecosystem?
Amazon referred to as the earths lungs, its 400 billion trees transport humidity inland from the Atlantic ocean taking 20 billion tonnes of water vapour daily from the forest and dumping it as rain on central and southern brazil. Amazon river carries 17 billion tonnes of water to the Atlantic every day.
Prolonged drought causes forest stress and sets up cahin reaction where younger trees die reducing canopy cover and therefore humidity ,water vapour and rainfall.
>With less tree cover exposed to sunlight litter and dying vegetation creates forest fires causing die back.
what are the impacts of drought on wetland ecosystem in particular the pantanal?
> The Pantanal is a large wetland area in central south America, 14000 km2 of which lie within brazil making it the most significant wetland ecosystem home to many rare species and birds.
> Seasonally flooded between april & nov. Flooding covers 80% of Pantanal & wetlands retain 60% of freshwater throughout the year.
> In 2014/15 drought tree mortality was increased reducing habitats for wild animals/ cattle and ecotourism
> wildfires became a major threat caused by ranchers burning old grass to clear vegetation.However these became an uncontrolled inferno, burning wetlands and forests.
Where in the UK is rain most common and why?
Northwest of the uk, combination of warm wet westerly winds-plus uplands such as the Cumbrian fells- creates orographic rainfall resulting in places such as cumbria being wettest places in england.
What was storm desmond created by?
Caused by deep alantic low pressure systems bringing prolonged and heavy rainfall through a ‘warm conveyor belt’
What were the immediate effects of storm desmond?
> Honister pass recorded 341.4mm of rain in just 24h
> 405mm of rain fell in Thirlmere in 38 hours.
> 5200 homes were flooded.
> Major roads and rail services were disrupted for several days
> landslide closed a section of the West Coast mainline between Preston and Carllisle.
> 61000 homes lost power when an electrical substation was flooded
where was the worst affected and What caused the flooding in storm desmond?
Major disruption, with the greatest impacts due to flooding. Carlisle was worst hit by severe flooding from the river Eden.
December flooding worsened by the already saturated ground- had been the second wettest month since 1910.
This wetness can be explained by the position of the jet stream. Driving force which determines the direction of depressions and their speed of movement this band of air remained on the Uk for longer than usual bringing in rainladen depressions from the Atlantic.
What physical factors caused the flooding in cumbria?
> Moist air mass stayed up over Cumbria for 48 hours- delivering record rain.
> cumbrian fells created orographic rainfall
> conyeyor of warm and moist air shifted towards to the UK from the Caribbean where sea temps were unusually high.
> too much rain for the already saturated ground to absorb. Overland flow carried water to rivers where it overflowed. Steep slopes accelerated this process.
> Impermable surfaces and sewers/drains blocked by debris, mean surface water flowed rapidly and directly into the already-overfilled river channels.
What were the long term ESE impacts of 2015 flooding in cumbria?
SOCIAL:
>5200 homes flooded –>leading to temporary accommodation
>local services such as schools had to close and many residents suffered phycological trauma
ECONOMIC:
>Many businesses closed, transport for infrastructure damaged
>cost of cumbria flooding was 100 million in 2005
>insurance claims caused by flooding exceeded 6 £ billion
>Houses prices fell and tourism was deterred.
ENVIROMENTAL:
>many river banks eroded, adding to flood risks with them full of debris and contaminated with sewage effluents/pollutants.
>soils eroded, habitats destroyed , with saturated ground leading to decomposition of dead animals giving off noxious gases poisoning ecosystems and saturated ground also caused landslides.
How has the Sahel been affected by climate change?
Variable rainfall in the Sahel region where rain varies from 100mm to 600mm per year. Up to 90% in the summer, as part of the West African monsoon.
> from 1970s to the 1980s rains faced decline of rainfall of up to 40%.
> sahels climate changing since 1996 as several wet years have persisted, offering the ability to convert dry landscapes to productive farmland.
> Re-greening is a restoration technique that involves planting trees and bushes, helping farmers benefit from increased yields, natural regeneration of water-retaining shrubs and low-cost foresting, and water-harvesting techniques.
How has the Sahel been affected by climate change?
Variable rainfall in the Sahel region where rain varies from 100mm to 600mm per year. Up to 90% in the summer, as part of the West African monsoon.
> from 1970s to the 1980s rains faced decline of rainfall of up to 40%.
> sahels climate changing since 1996 as several wet years have persisted, offering the ability to convert dry landscapes to productive farmland.
> Re-greening is a restoration technique that involves planting trees and bushes, helping farmers benefit from increased yields, natural regeneration of water retaining shrubs and low-cost foresting, and water-harvesting techniques.
How has the Sahel been affected by climate change?
Variable rainfall in the Sahel region where rain varies from 100mm to 600mm per year. Up to 90% in the summer, as part of the West African monsoon.
> from 1970s to the 1980s rains faced decline of rainfall of up to 40%.
> sahels climate changing since 1996 as several wet years have persisted, offering the ability to convert dry landscapes to productive farmland.
> Re-greening is a restoration technique that involves planting trees and bushes, helping farmers benefit from increased yields, natural regeneration of water-retaining shrubs and low-cost foresting, and water-harvesting techniques.
How has the Sahel been affected by climate change?
Variable rainfall in the Sahel region where rain varies from 100mm to 600mm per year. Up to 90% in the summer, as part of the West African monsoon.
> from 1970s to the 1980s rains faced decline of rainfall of up to 40%.
> sahels climate changing since 1996 as several wet years have persisted, offering the ability to convert dry landscapes to productive farmland.
> Re-greening is a restoration technique that involves planting trees and bushes, helping farmers benefit from increased yields, natural regeneration of water-retaining shrubs and low-cost foresting, and water-harvesting techniques.
How has California been affected by climate change- what has it caused and what has it led to?
> 40 million calis have increased problems with rainfall,3x the number of normal wildfires due to dry ground.
Scientists predict megadroughts lasting 30years with 2015 marking the 4th year of continous drought.
90% chance of decade-long drought
> Drought caused by 2 factors:
> increased temps which has increased evapouration
Fall in precipitation
> This has led to:
> Soil moisture levels have declined and forested arounds have turned to shrub and grassland.
Groundwater has decreased 30m in 4 years
reservoir levels have also fallen down 9%
permanent snow record low impactful as provides 1/3 of water used in cities and farms.
Examples of contested water resources?
China and india: conflict over the Brahmaputra river could be diverted into china to reduce water scarcity but it would decrease indias water supply.
China vs Myanmar, Cambodia, Laos, Thailand and Vietnam - Chinese dams along eith headwaters of mekong river threaten downstream nations.
Egypt vs Ethopia, Sudan, South sudan and Uganda- The Blue and White Nile basins supply Egypt with vital water by 85% of it comes from upstream where increasing demands could threaten egypts supplies.
Turkeys water budget:
> Input; 643mm of rain per year.
> 55% lost as evaporation and transpiration, 14% goes into groundwater and 15% unusable onlu 16% can be used.
What is GAP?
Turkey 3x size of the UK, summer drought in southeast and capitals have forced gov to invest 32 billion into south-east Anatolia project (GAP) attempt to increase incomes in anatolia, by developing water and energy supply.
> But scale of GAP has potential for conflict with neighbour syria and iraq as involves dams on Epharatas and Tigris rivers.
What are the aims of GAP?
The aims of GAP are to:
> construct 22 dams, 19 HEPS power plants and 2 water transfer tunnels.
>Provide irrigation for 1.7 million hectares (20% of Turkeys cultivable land)
>Diversify agriculture into cash crops
>Stop migration young people from the region by increasing jobs
>Help anatolian economy grow by 400% and wholw turkish economy to grow by 12%.
What are the aims of GAP?
The aims of GAP are to:
> construct 22 dams, 19 HEPS power plants and 2 water transfer tunnels.
>Provide irrigation for 1.7 million hectares (20% of Turkeys cultivable land)
>Diversify agriculture into cash crops
>Stop migration young people from the region by increasing jobs
>Help anatolian economy grow by 400% and wholw turkish economy to grow by 12%.
What and where is the Murray-Darling Basin and its uses?
Covers 1million km of southeastern australia. Contains 2 rivers- Murray and Darling
covers 14% of Australias land mass and covers 75% of australias water (85% of irrigation water), providing 40% of nations farm produce.
What are the threats to the MDB?
MDB under threat from increasing and competing demands.
>5x increase in water extraction since 1920s, which has not been well managed.
>Difficulties rise because MDB crosses multiple climates from rainforests to deserts because of Australias size ,together with variations in ENSO cycles, annual,seasonal and local variations occur.
>some areas of MDB recieve surplus rain and other parts are in defecit. Regulation of water needed to ensure all cities can recieve required water.
Who are the key players in the MDB?
> Agriculture with the MDB providing 85% of irrigation water
Urban residents in the major cities of southeastern australia.
industrial users eg. mining industry
aquaculture and freshwater fishing
leisure activities
local and state governments of Victoria, New South Wales and Queensland
enviromental groups
conservation agencies
indigenous people
