Water Supply Flashcards
Explain the hydrological cycle
Water in ocean > evaporation > air > condensation > clouds > precipitation or snow and ice > transpiration back to clouds or run off to ocean or percolation to water table to groundwater flow to ocean
Define and provide examples of renewable resources
Natural resources that can be replenished in a short period of time
e.g. biomass, geothermal, solar, wind, thermal, water
Define and provide examples of non-renewable resources
A non-renewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption
e.g. coal, fossil fuels
What is the distribution of water on earth?
Ocean - Most of the earth’s water is in the oceans, but is too salty to use or drink
Groundwater - Less easy to access; People are increasingly drawing from groundwater in places where there is insufficient surface fresh water
Ice caps, glaciers, rivers and lakes - Almost 69% of the earth’s freshwater is trapped in ice caps and glaciers, but they are usually inaccessible for people to use them
Define water footprint
The total volume of water (in cm3) used to produce the goods and services for a person in a year.
Describe domestic use of water
Domestic use accounts for the smallest percentage of all water used globally.
It is used mainly for consumption (e.g. drinking and cooking), Hygiene purpose (e.g. bathing and flushing the toilet) and Amenity use (e.g. washing the car and watering the garden)
Volume of water used will vary from household to household because of various reasons such as personal habits, number of members in the household and the types of household appliances used which require different amount of water.
Describe economic use of water
Agriculture uses the greatest amount of water globally. It refers to the growing of crops for human use, mainly for food.
In places where rainfall is low or irregular, more water is used because of irrigation-water is obtained from water bodies such as lakes, rivers, reservoirs and wells. It is sprayed or watered onto crops.
Irrigation helps crops to grow in dry areas such as the San Joaquin Valley in California, USA.
Global Industrial water usage accounts for about 22% of total water used.
It is used primarily for hydropower, nuclear power and thermal power generation as well as industrial processes such as manufacturing.
Large amounts of water are used for the manufacture, maintenance and cooling of power generators.
Many manufacturing processes create lots of heat due to friction and chemical reactions. Water is thus needed to cool down the machinery and equipment.
It is also used to clean the machinery and products.
Define and state the formula for fresh water availability
The amount of fresh water available to a country varies tremendously worldwide
Country’s total water resources (cm3)/ Total population
What are the 4 levels of fresh water availability?
Water security
Water vulnerability
Water stress
Water scarcity
Define water security
When a country has adequate and sustainable fresh water for human consumption and use more than 2,500 m3 per capita per year
Define water vulnerability
If fresh water availability is between 1,701 and 2,500m3
When a country may face a risk of water-related challenge (e.g., water scarcity, water stress)
Define water stress
If fresh water availability is between 1,001 and 1,700m3
Fresh water availability cannot match high water use (either withdrawals or consumption)
Define water scarcity
When fresh water availability falls below 1,000m3
it can refer to the lack of availability of water in the country OR the people’s inability to access the water due to the failure of government to ensure a regular supply OR a lack of adequate infrastructure.
Define water shortage
When level of water usage exceeds the water supply available
Define drought
A period of drier-than-normal conditions that results in water-related problems.
What are the social impacts of drought?
Water rationing (each household receives 150 to 200 litres each time the tanker comes by) Some women and children in the villages have to walk for long distance to fetch water
What are the economic impacts of drought
Farmers have to give up their land as the harvest is poor / crop yield is low
Cannot produce enough food crop for food or surplus to sell
Have to abandon their farmland and move to city to look for job
Some water supply provided by private tanker operators–expensive, the poor cannot afford
Some industries such as food and beverages which depend heavily on fresh water supply e.g. production of beer may have to stop production (How will this affect businesses and the locals ?)
Define pollution
Introduction of substances into the natural environment (air, water, land) that results in unpleasant or damaging effects to the environment and human health.
How does pollution affect water quality?
As a result of pollutants, drop in water quality
Water becomes unusable for people
Reduces supply of clean fresh water
Why does water shortage occur?
Rapid population growth
Leads to need for increased food production & increase in household consumption →this increases the demand for water.
-But water supply cannot keep up with such increasing demands.
Affluent lifestyles
With more money, people start to consume more water-intensive meat, goods and appliances
-Use more water for ornamental& leisure purposes
What is a dam?
A barrier to obstruct the flow of water, especially one made of earth, rock, masonry and/ or concrete, built across a stream or river.
Why do we build a dam?
1.Storage of water for human consumption irrigation industrial purpose 2. Generate hydroelectric power 3. Protect against flooding 4.provide a lake/reservoir for recreational activities such as swimming, boating, and fishing
