1. SCIENCE 8 Unit 1- Water Systems on Earth
Slideshow 1
Chapter 1 -The water cycle plays a
vital role on Earth
Section 1.3 – Sources of Fresh Water

2. 1.3 Sources of Fresh Water Lakes, ponds and wetlands Streams
and rivers
Ground water
Glaciers
Drainage basins
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3. Ground water is water that soaks into the ground
Rock/ground with good porosity allows more water to enter
More pores (spaces in the rock/soil), the better the porosity
An aquifer is a layer of porous rock that allows ground water to flow, almost like a river below the surface.
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4. Ground Water
Humans get fresh water from Reservoirs, natural or man-made Wells, drilled into aquifers down to the water table
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5. Q…Suggest some conditions which might increase run-off.
Precipitation becomes run-off as gravity pulls water down into the groundwater, a lake or an ocean basin.
Q…Suggest some conditions which
might increase run-off.
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6. Factors That Affect RunOff
Type of Surface - Soil vs Rock
Saturation of Ground – Saturated soil means more runoff
Slope - The Steeper the slope the more run off
Vegetation – Less Vegetation more runoff
Human Development – ie more runoff on concrete or pavement.
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7. Drainage Basins
Drainage basins are large areas where surface water all moves towards one main river
Run-off flows into streams and
smaller rivers, which are
tributaries of large rivers,
forming a branching system
See e 379
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8. There may be many small watersheds within a larger drainage basin.
Drainage Basins
Watershed
The area of land that drains into a body of water such as a river, pond, lake or ocean.
There may be many small watersheds within a larger drainage basin.
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9. 6 Major Drainage Basins in NL
Labrador Sea
Gulf of St. Lawrence
West Coast Gulf of St. Lawrence
South Coast Gulf of St. Lawrence
Atlantic Ocean Avalon Peninsula
Atlantic Ocean North-east Coast
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10. Almost 66% of all fresh water on Earth is in glaciers
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11. Alpine Glaciers (right) Found in mountain valleys
Continental Glaciers of Antarctica (above)
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12. Glaciers
Glaciers slow down the passage of water through the water cycle by storing vast quantities of water. They release the water during the hot summer months.
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13. Water trapped in glacial ice
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14. Glaciers covered ~ 20% of land on Earth.
The Ice Age
The most recent began
years ago ending
years ago.
Glaciers covered ~ 20% of land on Earth.
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15. The Ice Age
Why Do you think the coastline during the ice age differed from the modern coastline???
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16. Glaciers and Global Warming
In the last 100 years the average temperature has increased dramatically.
The world’s glaciers are melting at a quicker paces than ever before.
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17. Melting Greenland Glacier
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18. Receding Athabasca Glacier in Alberta It has receded
Glaciers and Global Warming
Receding Athabasca
Glacier in Alberta
It has receded
1.5 km since 1843.
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19. Glaciers and Global Warming
Q….Suggest Some implications of the glacier melting.
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20. Salinity of Oceans may decrease Flood rivers
What does this mean?
Sea Level may rise
Salinity of Oceans may decrease
Flood rivers
If glaciers disappear, rivers may dry up
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