Water Cycle Eq 3 Flashcards
Water stress
When the annual water supply of water falls below 1700m3
Water scarcity
When the annual supply of water per person falls below 1000m3
Physical scarcity
Occurs when more than 75% of a country’s or a regions blue water flows are being used- this currently applies to 25% of the worlds population
Economic scarcity
Occurs when the development of the blue water sources is limited by a lack of capital, technology and good governance
Virtual water
The hidden flow of water when food or other commodities are traded
Key causes of water insecurity
-over abstraction from rivers, lakes and groundwater aquifers
-water contamination from agriculture
-industrial water pollution
-climate variability
-saltwater encroachment
Industrial water pollution
-industrial waste is dumped into rivers and then ends up in oceans
-in China, 300 million people use contaminated water daily and 190 million suffer from water related illnesses annually
-untreated sewage disposal especially in developing countries causes water borne diseases such as typhoid, cholera and hepatitis
-estimated by WHO that by 2020, 135 million people could die from these diseases
Saltwater encroachment at the coast
-movement of saltwater into freshwater aquifers due to sea level rise, storm surges and human abstraction of groundwater from the water table
-this happens under natural conditions with the seaward movement of freshwater reducing saltwater enrichment in coastal zones
Over abstraction from rivers lakes and groundwater aquifers
-humans can over abstraction from rivers, lakes and groundwater sources for domestic purposes
-by 2025, total projected is to reach over 5000 cubic km per year
-until recently agriculture absorbed over 70% of extractions globally but industrial usage is rising especially in developed countries
Water contamination from agriculture
-expansion of commercial agriculture has led to increases in nitrate and phosphate fertiliser applications, causing eutrophication
-leads to excessive growth of plant life and death of animal life due to lack of oxygen
-many pesticides are banned in developed countries due to their health hazards
Climate variability
-global variations in the distribution of freshwater resources due to natural climate variability between arid and human climates
-climate change may increase this variability
-warmer climate in some locations increase rates of evaporation and transportation leading to less effective precipitation
-warmer water encourages growth of bacteria and other organisms that are harmful to human health
What is the water poverty index
An assessment of the degree of water shortage and the subsequent water insecurity problems
Factors influencing the price of water
-cost of obtaining the supply
-investment in infrastructure
-demand
-government policies
-privatisation
-lack of piped water supply
What percentage of freshwater withdrawal world wide is used for industry and energy?
20%
Aral sea location
-once one of the four largest lakes in the world (68,000 sq km)
-the northern part is in Kazakhstan
-southern in Uzbekistan
-western and central parts are covered in plains
-eastern part is occupied by mountain ranges (Himalayas)
Cause of the problem- Aral Sea
-in the 1930s, planners started to build canals to take water from the two main rivers
-in order to develop irrigated cotton and rice farming in the area
-in the 1960s more canals for irrigation were built
-70% of the irrigation water either leaked out of the canals or was evaporated from them
-less and less water flowed
Social impacts of Aral Sea
-people had to move away as few jobs were available
-High rate of respiratory disease in the area, especially tuberculosis
-cancer more widely particularly the throat
-growth of anaemia amongst local people as well as a kidney, eye and liver problems
Economic impacts- Aral Sea
-collapse of fishing industry
-many people became unemployed
-few jobs available in the new irrigated and rice farms
-local shops and services such as schools found it harder to survive and forced to close or amalgamate
Environmental impacts- Aral Sea
-as the sea shrank, water became more polluted and saline
-affected the local climate which became colder in winter and hotter in summer
-The dried out sea bed contained many chemical residue from pesticides and fertiliser as well as sewage residue
-huge toxic dust Storms by local winds
-70,00,000 tons of salt rose into the atmosphere
Arguments for the Gibe III dam
-growing population
-needed for hydroelectric power
-increase the capacity to generate electricity
-lots of jobs created
-allow Ethiopia to become an exporter of electricity to Kenya, Sudan and Djibouti
-support irrigation
-regulate flowing downstream
-double the electric capacity
Arguments against the dam
-high construction cost of $1.83 billion
-governments broke rules as they were in such a rush
-as they broke rules organisations such as the world bank would not fund the dam and lack of transparency
-half a million people live downstream
-broke international transparency rules such as the environmental impact
-environmental impact was done two years after construction started
-could lead to conflict between people fighting over scarce resources: mursi tribe and nyangaton tribe
Where is the river quaggy?
South east London, Lewisham and greenwich
What had been done to prevent the quaggy from flooding Greenwich?
Artificial channels and culverts were built to divert it beneath ground surface
What caused an increased flood risk in Lewisham and Greenwich?
Increased urban development
What kind of approach did the environment agency choose to deal with this increased flood risk?
Soft engineering
Why was sutcliffe park lowered and shaped?
To create a floodplain where water could collect naturally
Environmental benefits the river restoration scheme had
-reduced flooding
-restored wildlife
Advantages of Singapore water schemes
-self reliant
-sustainable
-good for environment
-less wastage
-reduced demand for water
-in control of own water supply
-cost falls on average 4%
Disadvantage of Singapore sustainable water schemes
-very expensive
-need huge quantities of energy
-high costs can be passed onto consumers
-locked into agreement with Malaysia who could use it as a political weapon or make it more expensive
What is NEWater?
High grade recycled water produced from used water that is treated and further purified using advanced membrane technologies and ultraviolet disinfection making it ultra clean and safe to drink
Rain water harvesting jars in Uganda pros
-close to home
-removes the need for people to travel far
-jars have long life and provide a stable source for many years
-relativity cheap materials used
-relatively straight forward
-encourages increased consumption
-deducted back strain or injury from carrying heavy water containers
Rain water harvesting jars in Uganda cons
-contaminated by bird droppings
-some poorly constructed jars can suffer from algal growth
-invasion by insects, lizards and rodents
-can act as a breeding ground for disease vectors
