sustainable management of water

Question 1

how do variations in precipitation affect the availability of water

Answer 1

the amount of precipitation that an area receives will determine how much water is available. this may result in floods or droughts

Question 2

what are floods

Answer 2

an overflow of a large amount of water onto what is normally dry land

flash floods and river floods are two common types of floods

flash floods are caused by exceptionally heavy rainfall over a short period of time

river floods are typically caused by sustained heavy rainfall

Question 3

how does a flood occur

Answer 3

1. an area receives a lot of rain over a sustained period of time
2. a large amount of water enters the river
3. the water level in the river rises quickly and the river overflows its banks

Question 4

how does a drought occur

Answer 4

1. an area receives very little rain over a long period of time
2. there is too little rainwater to replenish the river
3. the water level in the river drops gradually, until it eventually runs dry

Question 5

what are droughts

Answer 5

a drought is a long period of little or no rainfall in a specific area

Question 6

how does water support river ecosystems

Answer 6

precipitation provides a regular supply of water to rivers so that organisms can live in them. in other words, water supports the river ecosystems, which refers to the community of plants and animals found in rivers that interact with one another

Question 7

how do people use water

Answer 7

domestic, recreation, agriculture and industry

Question 8

how is water used for domestic purposes

Answer 8

using it for household activities like bathing, cooking and flushing the toilet

Question 9

how is water used for recreation

Answer 9

canoeing, sailing and fishing

Question 10

how is water used for agriculture

Answer 10

agriculture accounts for the largest use of water worldwide. it is used to grow crops and rear animals for human consumption.

Question 11

how is water used for industry

Answer 11

many industries require water to function. it is used to cool equipment in factories and power plants

Question 12

how do human actions lead to water pollution and its associated impact

Answer 12

human activities often cause water pollution for various reasons. some people may conveniently throw rubbish into drains, and factories may release toxic chemicals in the sea to save costs

Question 13

what does water pollution cause

Answer 13

it causes the water quality to fall

Question 14

does water pollution also affect aquatic ecosystems

Answer 14

yes

water pollution poses a threat to aquatic ecosystems. pollutants like pesticides and led kill plants and poison animals that feed on them

Question 15

how can water be managed sustainably

Answer 15

-improving water quality
-reducing water consumption
-improving water technologies
-importing water

these management strategies help to ensure that there is an adequate supply of water for human activities in both the short term as well as the long term

Question 16

how do countries improve water quality

Answer 16

countries can implement laws to maintain or improve water quality

Question 17

how do countries reduce water consumption

Answer 17

raise awareness and promote water conservation

Question 18

how do countries improve water technologies

Answer 18

countries are increasingly using technology to develop new ways of producing and conserving water. SG has been using desalination which is
1. pre-treatment (seawater undergoes processes such as screening and filtration to remove fine particles and microorganisms)
2. reverse osmosis (the pre-treated seawater is pumped at high pressure through semi-permeable membranes to separate dissolved solids)
3. conditioning and disinfection (the water is disinfected, re-mineralised and made potable by adding chemicals such as chlorine and floride)

Question 19

how do countries import water

Answer 19

SG is relatively scarce, have to rely on Malaysia to import water (1961 and 1962 agreement)