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Chapter 4 Sustainable Management of Water - Coggle Diagram
Chapter 4
Sustainable Management of Water
Unit 1
How Do Variations in Precipitation
Affect the Availability of Water?
the amount of precipitation that an area receives will determine how much water is available.
This may result in:
What are Floods?
an
overflow of a large amount of water
onto what is normally a dry land
e.g. flash floods, river floods
River Floods
caused by
sustained heavy rainfall or meltwater
the large amounts of rainwater and meltwater enter streams and tribunaries, which then flows into rivers
the
water level in the river rises
rapidly and eventually
overflows
the banks, flooding the surrounding areas
Flash Floods
caused by exceptionally
heavy rainfall over a short period of time
often
occur in dry areas
where there is not enough soil of vegetation to allow rainwater to infiltrate the ground
most of the rainwater becomes
surface runoff
which quickly floods low-lying areas
What are Droughts?
a
long period of little or no rainfall
in a specific area
may last for months or even years, causing areas to become drier than normal
there
may not be enough water available to replenish
the amount used for human activities or lost through evaporation and transpiration
reservoirs and groundwater will start to dry up
Unit 2
How Does Water Support River Ecosystems?
precipitation provides a regular supply of water to rivers so that organisms can live in them
Food Chain
shows the relationships among organisms as energy is transferred through food
phytoplankton → zooplankton → insects → fish → humans
Unit 3
How Do People Use Water?
domestic
recreation
agriculture
industry
How is Water Used for Domestic Purposes?
using water for household activities
e.g. bathing, cooking and flushing the toilet
How is Water Used for Recreation?
water sports
are highly dependent on water conditions and water quality
e.g. canoeing, sailing and sport fishing
How is Water Used for Industry?
to
cool equipment
in factories and power plants because they generate a lot of heat when they operate
to
generate electricity
when it passes through turbines installed in dams
as a
cleaning agent
in water fabrication (process of creating components for the electrical circuitry found in computers and mobile phones
How is Water Used for Agriculture?
accounts for the largest use of water worldwide
to
grow crops and rear animals
for human consumption
different animal and plant products require different amounts of water
Unit 4
How Do Human Actions Lead to Water Pollution and Its Associated Impact?
human activities often cause water pollution
water pollution occurs when harmful substances enter water bodies and cause water quality to fall
water pollution poses a threat to aquatic ecosystems
pesticides and lead kill plants and poison animals
Unit 5
How Can Water Be Managed Sustainably?
Countries around the world have attempted to manage water resources by:
improving water quality
reducing water consumption
improving water technologies
importing water
How Do Countries Improve Water Quality?
water quality
is determined by
temperature, amount of dissolved oxygen, turbidity and pH
these factors affect how well aquatic plants can grow and the range of aquatic animals that can survive
countries implement laws to maintain or improve water quality
e.g industries are not allowed to release wastewater into water bodies without permission from the NEA
How Do Countries Reduce Water Consumption?
water consumption increase as a country's economy and population grow
raise awareness and promote water conservation with the community, schools and businesses
e.g.
Water Efficiency Labelling Scheme (WELS)
grades water appliance with a tick rating (water-efficient products)
How Do Countries Improve Water Technologies?
using technology to develop new ways of producing and conserving water
e.g. "Four National Taps" - water from local catchment, imported water, NEWater and desalinated water
use of artificial intelligence to treat wastewater - machine first analyses how polluted the wastewater is and then suggests the most effective method to treat it
NEWater and desalinated water
reliable water sources that do not depend on the weather
helps SG better cope with the threat of climate change
through desalination, PUB turns seawater into drinking water using advanced membrane technolgy
SG has four desalination plants
e.g. Keppel Marina East Desalination Plant
Desalination
- Step 1 - Pre-treatment
Seawater undergoes
screening and filtration to remove fine particles and microorganisms
- Step 2 - Reverse Osmosis
Pre-treated water is
pumped at high pressure through semi-permeable membranes to separate dissolved solids
- Step 3 - Condition + Disinfection
Water is
disinfected, re-mineralised and made potable by adding chemicals
(chlorine and fluoride)
How Do Countries Import Water?
SG imports water from MY (agreements will expire in 2061)
Kuwait imports water from Serbia due to its dry climate