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Natural and Human Factors Affecting Our Water Supply
Transcript of Natural and Human Factors Affecting Our Water Supply
Some KEY TERMS
The Rising and Falling Water Table
Natural Water Table Changes
Floods, droughts and earthquakes are a type of natural occurrence that affect a watershed. Water Levels also naturally rise and fall due to water cycles from bodies of water and the atmosphere.
Human Causes of Water Table Changes
Human activities can also affect the water supply. Flooding can occur if a dam or other human-made water reservoir collapses. Most often, however, it is our overuse and misuse of water that hurts the supply.
1. Name two large user groups of our freshwater supplies.
You have a rain barrel outside your house that you use for water. The barrel can only recharge after rainfall.
What would happen if you were to use water faster than the supply in the barrel could recharge?
You would run out of water!
Like Rain Barrels, Watersheds receive a certain amount of water each year. If more water leaves a watershed than enters it a shortage will occur. Water levels in bodes of water and water tables will decrease too.
If more water fills a watershed than can leave it water would soak into the ground when it rains filling up the layers of soil and aquifers. If rain progresses the top of the water table would rise closer to the grounds surface. If the water does reach the surface it will result in a flood that would contaminate the drinking water and could result in property loss. Saltwater floods can contaminate drinking water.
Both Natural and Human Factors cause these changes in the water table.
Flooding can be caused by a number of variables. Some of these consist of by heavy rainfall, ice-jams, sudden spring thaws, and storms.
Flash Floods are floods that occur without much warning mainly due to sudden heavy rainfall
Droughts are long periods of little or no precipitation. Watersheds gradually begin to lose water because of these. Less groundwater collects and so the water table drops too.
Earthquakes directly have an effect on water tables. Water Tables can go down by 1 m making it harder to draw water from wells.
Overuse of Wells
Our groundwater is recharged through the water cycle. Dry summers or winters can result in less water sinking into the ground and being collected in aquifers. People who use wells must make sure to use water wisely when the water table is low.
Well A is unable to reach the aquifer as the water table is lower.
Well B is able to reach the aquifer
Farming and Industry Practices
Many large scale farms and industries need a large amount of water for use in their operations. For these reasons they are usually located near large bodies of water.
When the water is used it is discharged back into the environment.
to release or pour out.
Water can be discharged directly into a water body, the atmosphere, a waste water drainage system, or a ground filtration system. Usually the water is not as clean and in the same quantity of what was taken out.
Examples of large-scale water consumption:
Pulp and paper production
Water Diversion and Export
The bottled water industry also removes large quantities of water from our water supply. The majority of Canada’s bottled water industries are in Ontario, Quebec, and British Columbia.
Water is removed from springs, municipal water treatment systems, aquifers, and glaciers, lakes, and streams.
When more water is taken than can be recharged the height of water tables decrease.
When water is shipped to another location (exported) the water cannot be returned to it's source and therefore can't be returned to the watershed where it was extracted from.
ANSWER: 2 of either crop irrigation, power generation, pulp and paper production, mining, petroleum, tar sands, bottled water.
2. What causes a flash flood?
Sudden heavy or concentrated rainfall like that which you could see in a thunderstorm.
3. What is the difference between a water table and watershed?
A water table is the level below which the ground is saturated with water while a watershed is
an area of land where all the water eventually drains into one main water body, such as a stream, river, wetland, lake, or ocean.