Water management
Global availability
2,5% water is fresh water
Fresh water - water that contains less than 1000 mg per litre of dissolved solids, most often salt
Water stress - when demand for water exceeds the available amount of water during a certain time period
Economic water scarcity - When the demand for water isn't satisfied due to the lack of investment in water of lack of demand for water
Physical water scarcity - When there isn't enough water to satisfy both human demand and the demands of the ecosystem
Evotranspiration - the movement of water from the earth, by evaporation and plant transpiration to the atmosphere
Global reasons for water demand
Increase in manufacturing industry in developing and emerging countries
Increase in thermal electricity generation
Increase in domestic water use
Increase in meat production (uses 8-10 more times water than cereal production)
Increased water use for irrigation
Average of 3000 litres of water to produce daily food for a person, and population is increasing
Increasing demand for emerging/developing countries
Supply of fresh water improved, so water demand increased which could create water shortages as the water is being used
For example demand in China increased due to lack of water after 50 years, so large transfer schemes were set up
Increased demand from developed countries
Technological advances - home appliances use lot more water eg. dishwasher uses 3000 litres of water per year
Changes to personal hygiene - more bathrooms now in houses, and people bathe and shower more, increasing demand for water
Sport has increased - eg. golf uses lots of water to keep the courses green
Leisure has increased - more swimming pools in gardens and hotels
Reasons for difference in water between developed and developing countries
Agriculture - amount of water related to type of farming - developed countries with low rainfall have lots of irrigation - 75 litres per second
Developing countries don't have same technology so 2 litres per second
Industry - Developed countries use millions of litres eg. Walkers use 700 million litres per year, although 42% recycled
Developing countries businesses are smaller and run from home (cottage industries) which use little water
As large TNC's move to developing countries water usage increases
1 litre of coca-cola takes 3 litres of water, and there are 24 coca-cola plants in India
Domestic - used widely in developed countries - include showering, laundry, kitchens, swimming pools etc.
Many don't have piped water to homes in developing countries - women spend hours each day getting water
Water usage restricted to cooking and personal hygiene
Water supply problems in the UK
Imbalannce of the supply from rainfall and demand from population
Rainfall received by UK is very varied - north and west receive high amounts due to them being very mountainous, but highest demand is in the south east, where only 550mm is received per year - in the north 1500mm
Plentiful supply and low demand in the north and west, but short supply and high demand in the south and east
Ageing infrastructure
Many of the pipes that supply water to households in the UK are between 100-150 years old - high leakage problem
In 2009, water firms in the UK lost 3.29 billion litres of water due to leaks - 1/3 of the water supplied
2004-2009, Thames Water reduced leaks by replacing old pipes by 27% at cost of £1 billion
Cambridge, water utility is replacing 13km water mains a year and installing meters on pipes so leaks can be detected more quickly
There will always be leaks due to the environment and pressure of road traffic, but leaks must go down so UK has sufficient water supply in future
Sewage system of UK has ageing infrastructure which in many places is also over 100 years old
Before October 2011, much of sewage system owned by people who lived in the street, but 1st October most of the ownership was passed on to water companies who are responsible for maintaining the network and mending leaks
Sewage leaks do occur, due to old drains collapsing because of heavy traffic - not built to withstand volume and weight of traffic today
Seasonal imbalances
UK receives most of its rainfall in the winter but highest water demands are in the summer
Increased supply in developing/emerging countries
Increased in past 50 years mainly due to charitable organisations such as Water Aid UK who give people the means to provide themselves with drinking water
1990-2012 2.3 billion gained access to clean drinking water
2012 11% didn't have access, but in 2015, only 8% didn't have access
Little change in supply in developed countries
Changed little due to human intervention which kept supply up
Demand is lowest in the winter, so water from the winter months needs to be stored so that there there isn't water stress in the summer months
Water supply companies can have problems in the summer if it was hot, or if it was a mild winter or a dry spring
Also can be yearly variations so water stores in reservoirs can decrease
Supply problems in developing/emerging countries
Access to only untreated water
Due to lack of piped clean fresh water to households
748 million still lack access to improved clean water
Amazon, waste materials from mining and oil extraction are dumped into rivers, which pollutes the indigenous tribes water supply - increased risk of cancer, abortion, headaches and nausea, as large amounts of toxins
Untreated sewage - more than 80% in developing countries discharged untreated into rivers and lakes contaminated water causes diseases
Young and old particularly susceptible to diarrhoeal diseases related to dirty drinking water, however they decreased by nearly a million 1990-2012
Pollution of water courses
More than 840,000 people die from drinking water that has been polluted each year
Many still use dirty rivers for water as they have no other options
Bangladesh nearly 70 million drinking from wells which contains high arsenic levels - affects 140 million in 70 countries - worse as ground water cannot replenish due to increased demand as growing populations
Around 70% industrial waste developing countries is disposed of untreated into rivers which contaminates the water. In India and Africa, many wells contain nitrate levels too high due to intensive farming in the areas - from fertilisers (NPK)
Low annual rainfall
Many developing/emerging countries are in parts of the world with low annual rainfall
As populations increase, these populations have physical scarcity of water - estimated by 2025, 1.8 billion will be living in countries with water scarcity
Using technology to meet water supply demands
Diverting water and increasing storage
In Oklahoma, rainfall is infrequent but heavy
Surface water evaporates quickly so it is collected and diverted and stored in underground storage
Water transfer
Allows movement of water from areas of surplus with low demand to areas of deficit with high demand
China is building three canals system to transfer water from the Yangtze river in the south to the yellow river in the arid north - involves building dams and tunnels through mountains
Dams and reservoirs
Dam - wall built across a river to hold back water to create an artificial lake (reservoir)
Advantages - control flow of river, prevent floodings and help with irrigation
Disadvantages - expensive, can displace many people, may reduce the flow downstream and increase build up of pollution in the reservoir
Desalination
The removal of minerals from salt water to make it drinkable
Very expensive process and is only used in extreme circumstances
Both Saudi Arabia and UAE use desalination as they don't have high annual rainfall
16000 desalination plants worldwide producing 70 million cubic metres of fresh drinking water per day
Saudi Arabia has most desalination plants, with USA second
Takes a lot of energy but plant uses cheap supplies of oil and gas by using cheaper night time electricity, and by using solar power to operate the plants
Why do water resources require sustainable management
2.3 billion people were given access to clean drinking water 1990-2012 but 748 million still need improved access
Everyday 2 million tonnes human waste disposed of in water courses
In developing + emerging countries 70% industrial waste dumped untreated into water courses
By 2050 demand for water likely to increase by 55%
Increase in population so increase in meat production - requires 8-10 times more water than cereal crops
Worlds population growing by 80 million a year - demand for water increase by 64 billion cubic metres each year
Worldwide 70% water that is withdrawn from river goes to agriculture for food - irrigated land represents 20% land used for farming but contributes 40% global food crop
How has UK attempted to manage water resources in sustainable way
Water transfer schemes - eg. Elan valley supplies Birmingham
Government passed policies to ensure water companies manage water sustainably - 25 year plans to show their use of water sources
Water obtained from aquifers - water bearing rocks
Government set efficiency targets for for water supply companies
Websites available to help people save water in their homes, sponsored by government
Government begun to lower licences granted to water companies for ground water extraction - allow ground water supplies to replenish
Focusing on management of river catchment areas
Since targets on water companies in 1990's, leakage down by 35% and 2005-2010 water companies renewed or laid around 20,000km of water mains
How has China attempted to manage its water resources in a sustainable way
Problems
Over 70% China's rivers and lakes are polluted
Past 50 years population of China has doubled but water demand increased by 5.5 times
Western, central and north-east regions of China suffer from recurring drought - 18 million people short of water
China has high population density in the northeast which has lower rainfall than southeast
Around 1500 die in floods each year, 2/3 population producing 70% China's agricultural produce live on floodplains of major rivers
Solutions
2010-2012 government carried out a water census - 800,000 surveyors were trained and sent around country to find out how waster was being used in rural and urban areas - also reported on conditions of lakes and rivers and any other water conservation projects
Desalination plants being built to provide cities in the north with water at cost of £2.1 billion - triple water availability by 2020
Water being directed from China's wetter south to north of the country with physical scarcity of water - diversion project
Projects in rural China by charities to try cut amount of water used by farmers by using irrigation methods that save 65% water annually and improve crop production
Government sending in Olympic athletes into schools to inspire children to save water - in Beijing entered 1,000 primary schools giving out leaflets and encouraged children to post water saving tips around the school
Beijing has water conservancy museum which aims to show people how much water they use in their daily lives - heighten awareness
In Shanghai 50 wells dug 240 metres deep beneath large residential areas - water from these wells used when there are acute water shortages, and city is also building water treatment plants and reservoirs
China spent money on improving its reservoirs - by 2015 over 50,000 reservoirs had been reinforced and their water quality improved