water EQ3 Flashcards
define water stress
below 1700 m^3 per person
define water scarcity
below 1000m^3 per person
define absolute water scarcity
less than 500m^3 per person
what is water insecurity
water insecurity occurs when economic, social and environmental requirements for water supplies are not met
what are the two physical causes of water insecurity
-climate variability
-saltwater encroachment
a physical cause of water insecurity is climate variability, explain this
there are significant global variations in the distribution and variation of freshwater resources due to climate variability (arid vs wet). Climate change is amplifying this, changes in runoff and aquifer recharge. warmer climates= increased rates of evaporation and transpiration = less effective precipitation. Warmer waters= encourage the growth of bacteria and other organisms harmful to human health. Thermal pollution can degrade water
a physical cause of water insecurity is saltwater encroachment, explain this
global level sea rise and localised abstraction of groundwater are increasing the risk of saltwater intrusion into many coastal areas. Extensive groundwater pumping reduces the water table and allows saltwater to move into aquifers and soils.
case study for saltwater intrusion and climate variability, the Pacific islands
-35% of Samoas water supply is drawn from aquifers.
-Climate variability associated with ENSO cycles is causing recurrent droughts and floods.
-During the 1997/8 El Nino event, groundwater withdrawal levels in the Marshall islands nearly tripled as a result of drought. Affects crop production.
how is water needed to ensure economic sustainability
-water is needed for food, energy and manufactured products.
-around 20% of all cultivated land is irrigated
-energy production is water intensive
-industrial processes will affect water supply and quality.
-pollution occurs in the industry
what are the complications to the environment due to human activities
a half of wetlands have been lost
disruption of ecosystems through urban sprawl , over abstraction and deforestation and pollution.
may erode an environments capacity to sustain itself
untreated water= breeding ground; disease vectors such as mosquitoes. An inadequate water supply will lead to over abstraction= prolonged periods of drought= desertification
what are the two human causes of water insecurity
overabstraction
water contamination
how does the human cause of over abstraction affect water insecurity
its estimated that over 20% of the worlds aquifers are overexploited. This is due to ever increasing demands due to population growth , rising middle class, water is needed for agriculture
how does the human cause of water contamination affect water insecurity
due to fertilisers and pesticides in farming, industrial production, mining, untreated sewerage and urban runoff and waste water. Some countries dont have water infrastructure to treat water. Eutrophication.
In 2015, over 1 mill m^3 of contaminated water was released into the Animas river
the Nile, Transboundary water conflicts case study
11 countries use the river Nile
-Egypt depend on the Nile for 95% of its H2O needs
- ambitious dam building programmes have the potential to reduce downstream flows.
-The Nile agreement gave Egypt the right to veto power over construction projects.
-It was announced in 2011 that the Grand Ethiopia Renaissance Dam was to be built, this caused tensions between Egypt and Ethiopia but was resolved, Egypt and Sudan signed an agreement
what are the spheres of pressures for water insecurity
Diminishing supply
- climate change
-pollution
-competing users
Rising demands
-population growth
-economic development
competing demands from users
-international issues
-upstream vs downstream
-HEP vs irrigation
whats the WPI
the water poverty index. It uses measurements to assess water insecurity. Water poverty decreases as the score increases
Ethiopia, what are the conflicts between users in Ethiopia
- The Gigel Gibe III Dam and hydroelectric plant is located in Ethiopia
- will prevent seasonal floods for downstream populations (Indigenous people)
-estimated that more than 200,000 people rely on the dam for subsidence agriculture. Dependent on seasonal floods to replenish dry soils for planting
-ethnic groups= chronic hunger
-supporting the dam= artificial floods can be released, and projects are planned for plantations.
-However, these plantations may only benefit Ethiopian state owned companies.
-In 2011, UNESCO halted the dam construction as it was estimated that there were significant impacts for lake Turkana
What are the hard engineering techniques for managing water supply
-transfers
-mega dams
-desalination plants
China case study: South North water transfer
80% of Chinas water is in the South while half the population is in the North
-the project has the capacity to deliver 25 billion m^3 of freshwater per year from the Yangtze river.
- Very expensive, costs reached $80 billion in 2015.
-more than 300,00 people were displaced during the building of the central route.
-The transfer of water does not address the underlying causes of water shortages in the North which is due to inefficient agriculture, urban use and pollution.
-sustainability: several droughts in the Yangtze has caused water shortages so this transfer would increase the risk of this.
case study: Mega Dams
Gigel Gibe III dam.
The Three Gorges Dam-> to control flooding on the Yangtze river and generate HEP. Surplus of water can be used for the South North transfer. 1.2 million people relocated. Uses renewable energy. Expensive
case study: desalination
Israel’s desalination plants.
-provides a reliable and predictable supply of water, takes water directly from the Mediterranean sea. Aims to provide 70% of Israel’s domestic water supply by 2020.
-each plant requires its own power station and adds co2 emissions
what are the sustainable methods in restoring water supply
smart irrigation
recycling of water
water jars
case study: smart irrigation and water supply
-provides plants with suboptimal water supply causing mild stress, this conserves water and has been done in China.
-winter wheat production in North China plains has showed savings of 25% or more.
May be costly to implement
Highly sustainable as water isnt wasted and prevents evaporation losses.
case study: recycling of water and water supply
occurring in Singapore
recycled water (NEW water) is high grade recycled water that is produced from used water that is treated and further purified using advanced membrane technologies and ultraviolet disinfection. By 2060, PUB in singapore aims to meet 55% of water demands with NEW water
case study: Uganda jars and water supply
water aid NGO raises funds to improve access to all water
local builders have been trained in the construction of rainwater harvesting jars
have the capacity to collect 1500 litres of rainwater from roofs.
prevents people from having to walk far for water and has a long life span
poorer countries dependent on NGOs
water jars made from locally available materials
who is a global player in water supply
the UN
basin management at colorado
what are the berlin rules on water resources
9 rules
what factor shows that the berlin rules are hard to implement
ongoing conflicts in the Nile basin represent the ongoing difficulties in implementing Berlin rules and the global challenge to effective water sharing
