Summary

AGRICULTURE Major use of water as we struggle to meet food

demands of a rising population Uses 69% of the world’s fresh water supply Some forms of agriculture are less water-efficient than

others 17% of global area devoted to growing crops is

irrigated, poor management of these irrigation systems leads to problems of evaporation, seepage, salinisation and fertiliser problems

Summary

INDUSTRY 21% of global water used for industry Estimates for the coming decade suggest a rapid

rise in this amount as India and China continue to develop

HEP continues to use huge amounts of water, but this water is available to others once it has passed through turbines

Industry is much more efficient at using water (paper manufacturing is an exception)

Poses significant problems in terms of pollution

Summary

DOMESTIC Smallest category of consumption, using only 10% Amount used varies dramatically from country to

country Global domestic demands seems to be doubling

every 20years and it is arguably only the poor access in Africa that is limiting growth in demand there

The quality of water involved also varies dramatically

What’s happened?

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Human Impacts on water availability

WATER CONFLICTSTo build up a Case study about the Aral Sea

To understand how man can have a negative impact upon an area by changing the water supply

To discover possible solutions to reverse the environmental disaster

Human activity

Human activity can have a negative effect on the water environment

Pollution caused by human activity and excessive abstraction of water supplies can further increase water stress

Pollution of groundwater is much less obvious than surface-water pollution

Human activity

Draw a table to classify all of the pollutants into DOMESTIC,

AGRICULTURAL and INDUSTRIAL

Causes a range of diseases such as cholera and dysentery etc.

Consumes oxygen in the water and kills many organisms.

Can poison stretches of river completely killing all life.

Leads to eutrophication (water is deprived of oxygen by rich nutrients).

High toxic – even at low concentrations – causes the death of most river life.Affects the colour of the water and kills fish/shellfish.

Can lead to cancer.

Increases the rate of decomposition of biodegradable waste, reducing the water’s ability to hold oxygen.

Sewage disposal in developing countries will causes 135 million deaths by 2020

The UK adds 1, 400 million litres of sewage daily into our rivers.

Each year the world generates 400 billion tonnes of industrial waste.

Dams can collect sediments reducing soil fertility and prevent fish flows damaging ecosystems

Task:At the bottom of the same table classify the

impacts of pollution using your previous table.Which category has the worst impact? Explain

your answer

Abstraction and Salinity

ABSTRACTION

Removing water from ground water sources can have unintended consequences on the environment.

1. Worldwide water is being taken from aquifers faster then it can be replaced. In arid areas rainfall can never recharge these underground stores.

2. Removal of freshwater from coastal areas can upset the natural balance of saline and freshwater, which can lead to salt water incursions.

Abstraction and Salinity

SALINISATION

Irrigated water contains mineral salts. In arid areas the salts (Mg, Na, Ca) can become concentrated in the soil as the water table rises – leaving salt crystals behind. Stalinisation can destroy the land irrigation was meant to improve.

The salt can be washed away with rain water but the soil itself may become leached breaking down the soil structure. The salts can end up in rivers causing salinity for land further down stream.

Aral Sea

Located on the border between Uzbekistan and Kazakhstan

Once the world’s fourth largest inland sea (68 000km2) but it has been steadily shrinking since the 1960s

http://www.youtube.com/watch?v=Z0Pi61SyVSM

So what happened?

In the 1950s the Soviet government diverted much of the water from the rivers Amu Darya and Syr Darya, which fed into the Aral Sea, for irrigation of agriculture

By 2007 the sea had declined to just 10% of its original size and spilt into separate lakes, and its level had fallen by up to 40m

This is an environmental catastrophe

Environmental Effects

By 1960, between 20 and 60 cubic kilometres of water were going each year to the land instead of the sea. Most of the sea's water supply had been diverted, and in the 1960s the Aral Sea began to shrink

From 1961 to 1970, the Aral's sea level fell at an average of 20 cm a year and by the 1980s it continued to drop, now with a mean of 80–0 cm each year. The rate of water usage for irrigation continued to increase: the amount of water taken from the rivers doubled between 1960 and 2000. A strip of land now runs through the Sea.

The salinity of the Aral Sea has also risen from 10 g/L to 45 g/L the average salinity of the other Seas is around 35 g/L this has a massive effect on the ecosystem and what animals can live in and around the Sea.

Human, Economic and Social effects

The Aral sea has a huge economic effect on the area as they can no longer use the Aral sea to make money

Humans are also effected by the change to the Aral Sea as due to the lack of fishing people cannot get jobs. It also means that they cannot get as much food to feed themselves and their families. Nearly 60 000 people migrated away abandoning their fishing fleets.

The Aral seas reduction will slowly destroy the town as they may have fight over food and money. This is down to the lack of jobs in the area.

Human diseases

Diseases spread such as cancer, anaemia and tuberculosis occur

The human misery is huge. One victim has tuberculosis, which is rife and on the increase in the rest of the population.

Cancers, lung disease and infant mortality are 30 times higher than they used to be because the drinking water is heavily polluted with salt, cotton fertilisers and pesticides

The sea has become too salty and the water contaminated the groundwater supply. Many become very ill or anaemic

Human, Economic and Social effects

Key Players/Stakeholders

The former Soviet government Communist leaders began an ambitious irrigation

scheme designed to develop fruit and cotton farming in what had been an unproductive region and create jobs for millions of farm workers

Key Players/Stakeholders

For the remaining stakeholders consider the impacts of this irrigation scheme The fishing community Local residents Uzbekistan government Scientists Kazakhstan Farmers International Economists Water Engineers

How will they have been impacted? Could be positive or negative

Key Players/Stakeholders

The fishing community A once prosperous industry that employed 60,000

people in villages around the lakeshores collapsed Unemployment and economic hardship followed Shops lie useless on the exposed seabed

Key Players/Stakeholders

Local residents Health problems caused by wind-blown salt and dust

from the dried out seabed Drinking water and parts of the remaining sea have

become heavily polluted as a result of weapons testing, industrial projects, and pesticides and fertiliser runoff

Infant mortality rates are among the highest in the world, with 10% of children dying in their first year, mainly of kidney and heart failure

Key Players/Stakeholders

The Uzbekistan government The irrigation schemes based on the Aral Sea allow

this poor country, with few resources to remain one of the world’s largest exporters of cotton

It also hopes to discover oil deposits beneath the dry seabed

Key Players/Stakeholders

Scientists Only 160 of the region’ 310 bird species, 32 of the

70 mammal species and very few of the 24 fish species remain

The climate has changed too, making the area even more arid and prone to greater extremes of temperature

Key Players/Stakeholders

Kazakhstan Farmers Irrigation has brought the water table to the surface,

making drinking water and food crops salty and polluted

Key Players/Stakeholders

International Economists People in the region may no longer be able to feed

themselves because the land has become so infertile

Up to 10 million people may be forced to migrate and become environmental refugees

Key Players/Stakeholders

Water Engineers Inspections have revealed that many of the irrigation

canals were poorly built, allowing water to leak out or evaporate

The main Kara Kum Canal, the largest in central Asia, allows 30 to 75% of its water to go to waste

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The irrigation scheme fulfilled it’s aims, but is it worth

it?