Chapter 4 Flashcards
What are floods and what are types of floods are there?
A flood is an overflow of a large amount of water onto what is normally dry land. Two common types of floods are flash floods and river floods.
What are flash floods caused by?
Flash floods are 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 rainwater to infiltrate the ground. Therefore, most of the rainwater that fall onto the ground becomes surface run-off, which quickly floods low-lying areas.
What are river floods caused by?
Reserve floods are typically caused by sustained heavy rainfall or melt water produced when snow and ice started to melt in the spring season. The large amount of rain water and melt waterenter stream, which then flow into rivers. Water rises rapidly and eventually overflows the banks, flooding in the surrounding areas.
What are droughts?
A drought is a long period of little to no rainfall in a specific area. Route Nila for months or even years, causing areas to become right than normal. There may not be enough water available to replenish the amount used for human activities are lost through evaporation and transpiration. As a result, water stores, such as reservoir and groundwater will start to dry up.
How is water used by people?
Domestic purposes, recreational purposes, agriculture, and industrial purposes.
How is water used for domestic purposes.
Using water for household activities is known as the domestic use of water. (For an example, in Singapore, bathing cooking and flushing the toilet account for the highest percentages of domestic water usage.)
How is water used for recreation?
Water enables people to carry out certain recreational activities like canoeing, sailing, and sport fishing, which are highly dependent on water condition as well as water quality. This is known as the recreational use of water.
How is water used for agriculture?
Agriculture accounts for the largest use of water worldwide. Water is used to grow crops and rear animals for human consumption. Different animals and plant products require different amounts of water.
How is water used for industry?
Many industries need water to function as water is used to cool equipment in factories and power plants as they generate a lot of heat when they operate and is used to generate electricity when it passes through turbines installed in dams.
Causes of water pollution?
-Some people may conveniently throw rubbish into drains or the sea as it is convenient for them
-Factories may release toxic chemicals and used water into the sea to save costs.
-Some countries may not have the proper systems to treat wastewater.
-Some countries may have accumulated so much waste that their landfills have started to leak.
-Ships can leak oil into the sea, contaminating the water.
What is water pollution?
Water pollution occurs when harmful substances enter water bodies and cause water quality to fall, causing the amount of clean water to be reduced.
How does water pollution pose a threat to aquatic ecosystems?
-Pollutants like pesticides and lead kill plants and poison animals that feed on them.
-Excess fertilisers form farms that get washed into rivers by the rain provide additional nutrients for algae to grow rapidly, which take in oxygen during the process, causing fish and other aquatic animals to die due to a lack of oxygen int he water.
How can water be managed?
Improving water quality, reducing water consumption, improving water technologies and importing water.
How do countries improve water quality?
Water quality is determined by considering factors like temperature, amount of dissolved oxygen , turbidity and pH. Defectors affect how well aquatic plants can grow, as well as the range of aquatic animals that can survive. Countries often implement laws to maintain or improve water quality.
How do countries reduce water consumption?
Consumption tends to increase as a country’s economy and population grows, since water is needed support industries and need the daily needs of people. Although water is a renewable source it needs to be treated and cleaned and can run out if it used faster then it can be replenished. This is why countries encourage people to conserve and treasure water. For example, in Singapore, PUB, Singapore’s National Water Agency, works closely with the community, schools and businesses to raise awareness and promote water conservation. For instance, the Water Efficiency Labelling Scheme, grades water appliances with a tick rating so that people are more aware of more water efficient products in the market. PUB’s target is to lower Singapore’s per capita average household water consumption to 130 litres by 2030.
How do countries improve water technologies?
Countries are increasingly using technology developing ways of producing and conserving water. For example, Singapore has built a diversified and sustainable water supply known as the “four national taps” water from local catchment, imported water, NEWater and desalinated water. NEWater and desalinated water are reliable waters sources that don’t depend on water, helping Singapore better cope with the threat of climate change. These have been possible through years of innovation and continuous investment in research and technology.
How do countries import water?
Countries which have relatively abundant water resources may allow their neighbours to import water from them. for example, Singapore import water from Malaysia.
