CHAPTER 4: SUSTAINABLE MANAGEMENT OF WATER Flashcards
how do variations in precipitation affect the availability of water?
Amount of precipitation an area receives determines how much water is available resulting in floods and droughts.
What are floods? Name 2 common types of floods.
Floods are an overflow of a large amount of water onto what is normally dry land.
How does a flood occur?/ River flood
When an area receives a lot of rainfall over a sustained period of time/meltwater produced when snow and ice start to melt in the spring season, a large amount of meltwater and rainwater enters the river(through streams and tributaries) and the water level in the river overflows its banks.
What are Flash floods and where do they occur?
Caused by exceptionally heavy rainfall over a short period of time. These floods often occur in dry areas where there is not enough soil or vegetation to allow rainfall to infiltrate the ground. Therefore the rainfall becomes surface runoff which floods low-lying areas.
What are droughts? How long do they last?
Droughts are a long period of little to no rainfall in a specific area, which can last for years causing areas to become more dryer than normal. Water stores like rivers and ground water will start to dry up.
How does a drought occur?
An area receives very little rain over a long period of time and there is too little rainwater to replenish the river. The water level in the river will then drop gradually, eventually running dry.
How does water support river ecosystems?
Precipitation provides a large supply of water to rivers so that organisms can live in them, meaning that water supports the ecosystem, which refers to the communities of plants and animals found in rivers that interact with one another. For example, a food chain.
How is water used for domestic purposes?
Using water for household activities(bathing, cooking, flushing the toilet) is known as domestic use of water.
How is water used for recreation?
When people use water to carry out recreational activities(water sports like canoeing, sailing, fishing which are highly dependent on water conditions and quality), this is called the recreational use of water.
How is water used for agriculture?
Water is used to grow crops and raer animals for human consumption. Agriculture has the largest use of water worldwide. (different plants and animals require different amounts of water)
How is water used for industry?
Industries require water to functions
they use it to cool of their equipment and power plants as they produce a lot of heat when operating.
And water is also used to generate electricity when it passes through turbines installed in dams.
Water is also used as a cleaning agent.
How do human Actions lead to water pollution?
Humans
- conveniently throw rubbish into drains
-factories release harmful toxic chemicals in the sea to save costs.
Some countries do not have proper systems to treat waste water while others have accumulated so much waste, their landfills have started to leak into the oceans.
How does water pollution occur? Give an example.
When harmful substances enter water bodies and cause the water quality to fail. Water that is clean enough to use is thus reduced.
One third of the rivers in Africa and Asia are already affected by water pollution despite being a source of water for millions of people.
What is water pollution’s associated impact?
Water pollution poses a threat to the aquatic ecosystems as pollutants(lead and pesticides) kill plants and poison animals that feed on them.
Excess fertilizers from farms get washed into rivers by rain and provides extra nutrients for algae to grow rapidly. When the algae eventually dies, they are decomposed by bacteria which take in oxygen. There will be less oxygen in the water causing the other aquatic animals to die.
How can water be managed sustainably?
By improving water quality, reducing water consumption, improving water technologies and importing water.
