Water supply and environmental risks

Last time

Before we start: last time, in Map work and geographical investigations, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.

Clean water and a clean environment

Millions of people still lack safe drinking water, and economic development can pollute air, water and land. This lesson covers how water is supplied and used, and the environmental risks of development, with ways to reduce them.

Sources of water

Surface water: rivers, lakes and reservoirs behind dams. Groundwater: from wells and boreholes that reach aquifers, rocks that hold water. Desalination turns sea water into fresh water, but uses a lot of energy.

How water is used

In LEDCs, most water is used for agriculture, especially irrigation. In MEDCs, a larger share is used by industry and in homes. Use rises with population growth, irrigation and industry.

Water shortages

Causes: low rainfall, drought, over-use of groundwater, pollution, and growing demand. Effects: disease from unsafe water, crop failure, and time spent collecting water, often by women and children. Solutions: dams, wells, rainwater harvesting, water treatment, and using water more efficiently, such as drip irrigation.

Air pollution

Sources: burning fossil fuels in power stations, factories and vehicles, releasing carbon monoxide, nitrogen oxides and sulfur oxides. Effects: breathing problems, smog in cities, and acid rain, which damages forests, lakes and buildings. Reductions: catalytic converters, cleaner fuels, filters on chimneys, and public transport.

Water and land pollution

Water pollution: sewage, factory waste and farm chemicals, which kill fish and spread disease. Land: soil erosion from deforestation and over-grazing, and dumping of waste. Solutions: treating waste, controlling chemical use, replanting trees, and recycling.

Development and the environment

Economic development brings jobs and higher living standards, but often more pollution and resource use. Sustainable development meets today's needs without harming future generations. Laws, international agreements and new technology help reduce environmental risks.

Pollution at a glance

The main types of pollution, their sources and effects.

Mistakes that lose marks

Mistake one: using statistics when told not to. Mistake two: listing pollution sources without effects. Mistake three: saying LEDCs use most water in homes. The fix: source, effect, and solution.

The full-marks tip

The full-marks tip: for each environmental risk, give its source, its effect on people and the environment, and a solution. When reading a graph, follow the instruction about statistics.

On one card

So, on one card: water and environmental risks. Keep it for revision.