1. Chapter 1: Fresh Water
1.1 Water on Earth

2. Importance of Water
Makes up 2/3 of your body; helps digest food, grow, develop, etc.
Plants use water in photosynthesis to make food from the sun’s energy.
Water is a habitat (place where something lives and survives) for many organisms.

3. Where is Water?
Makes up approximately ¾ of Earth’s surface, with about 97% of it being salt water and only 3% being fresh.
About 2/3 of Earth’s fresh water is frozen in masses of ice, while most of the remaining 1/3 is underground.
The water we see (lakes, rivers, etc.) is only a tiny fraction of Earth’s water.

4. Where is Water?
Four oceans: Pacific, Atlantic, Indian, and Arctic; but they are really all connected.
Pacific is largest, followed by Atlantic.
Smaller saltwater bodies are seas.

5. Where is Water?
Ice sheets (glaciers) cover a great amount of land; icebergs are smaller pieces broken from glaciers that float.

6. Where is Water?
Rivers/Lakes – the Great Lakes contain about 20% of the Earth’s freshwater from lakes.

7. Where is Water?
Groundwater: water that fills the cracks and spaces in underground soil and rock layers

8. The Water Cycle (Review)
Water cycle: continuous process by which water moves from Earth’s surface to the atmosphere and back.

9. The Water Cycle (Review)
Evaporation: molecules at the surface change into a gas (water vapor).
Transpiration: evaporation from a plant’s stomata
Condensation: water vapor cools as it rises and joins together to form droplets, forming clouds.

10. The Water Cycle (Review)
Precipitation: water that condenses in the sky falls back to Earth’s surface as rain, snow, hail, and sleet.
Most falls into ocean
Source of almost all of the fresh water on Earth

11. Chapter 1: Fresh Water
1.2 Surface Water

12. River Systems
Rivers are formed from streams joining together; all of these flowing bodies of water make up the river system.
Tributary: streams/small rivers that flow into larger rivers; flow downward by gravity.

13. River Systems All water in a river system flows into a main river.
Watershed (drainage basin): land area that supplies water to a river system
The Mississippi River’s watershed covers about 1/3 of the US.

14. River Systems

15. River Systems
Watersheds are separated by divides, which are ridges of land (such as a mountain).
The Great Divide, or Continental Divide, is the longest divide in N. America.

16. Ponds and Lakes
Ponds and lakes both contain still water, usually supplied by precipitation, runoff, and groundwater.

17. Ponds and Lakes
Ponds are smaller and shallower; sunlight can reach the bottom of a pond.
Lakes are larger and deeper; sunlight cannot reach the bottom of a lake.

18. Ponds Plants grow at the bottom , along with bacteria and algae.
These produce oxygen, which helps sustain life for some animals.

19. Lakes
Little sunlight reaches the bottom, so fewer plants are able to survive in the depths.
Mollusks, worms, and fish can survive in the colder waters.

20. Lake Formation
Some lakes are formed by depressions from glaciers moving over the land (Great Lakes).
Others form in rift valleys.
Some form in volcanoes.
Some are man-made; reservoirs are used to store water for human use.

21. Eutrophication
Eutrophication: the process of nutrients building up on the bottom of the lake.
Algae uses these nutrients to spread, eventually blocking the sunlight, preventing organisms from living in the lake.
The organisms in the lake decay, filling in the water.

22. Chapter 1: Fresh Water
1.3 Water Underground

23. Groundwater Water moves underground through layers of soil and rock.
Different layers have different amounts of space to allow water to flow through.
The larger the pores, the easier it is for water to flow.

24. Permeable vs. Impermeable

25. Water Zones
Unsaturated zone: layers that contain water and air that are not full of water.
The layer that is completely full with water saturation zone.
The top of the saturation zone is called the water table.

26. Water Zones

27. Aquifers
Aquifer: an underground layer of permeable rock or sediment that contains water.
If the water is taken from the aquifer too fast, it might dry out.
The water in an aquifer is constantly moving – up, down, and to the sides.
However, it moves very slowly, so some of the water has been in the same aquifer for thousands of years.

28. Aquifers Three things are needed for an aquifer to form:
1. a layer of permeable materials stores water.
2. a neighboring area of impermeable rock keeps the water from draining away.
3. a source of water replenishes/refills the aquifer.

29. Springs
Spring: a flow of water from the ground at a place where the surface of the land dips below the water table.
found naturally.
Fresh, clean water.

30. Wells
Well: a hole in the ground that reaches down to the saturation zone below the water table.
Usually a pump is used to draw water from the ground, and a screen is used to filter out particles.
Wells can run dry if water is used more quickly than it can be replaced.

31. Artesian Wells
Artesian Well: well in which water flows to the surface naturally due to pressure.

32. Hot Springs
Hot spring: a place where hot water underground reaches the surface; continual flow of hot water.
Water sinks into the ground in certain places so deep that it is heated by the rocks underground, and has so much pressure applied to it that it shoots out of the ground.

33. Geysers
Geyser: a type of hot spring; water shoots into the air like a fountain of water and steam.
Yellowstone has over 300 geysers. Old Faithful shoots water about 20 times a day, lasting minutes.
Old Faithful

34. Chapter 1: Fresh Water
The Amazing Wetlands

35. Clean and Safe Fresh Water Human Use

36. Environmental Protection Agency (EPA)
Agency that sets standards for clean, safe water.
If water does not meet the standards, then it has to be “treated”.

37. Treating water – Step 1
Water is sent to treatment plants in pipes.

38. Treating water – Step 2
2. Water goes through a mixer with chemicals and clumping agent.

39. Treating Water – Step 3
3. Water goes into clarifying pool and sediments sink down.

40. Treating Water – Step 4
4. Water goes through layers of sand, gravel, etc. to filter.

41. Treating water – Step 5
5. Chlorine is added to kill bacteria.

42. Waste water treatment
Waste water must also be treated before it can be reused.
Sewage system or Septic system

43. Sewage system treatment
System collects and treats waste water from a whole city or town.
Part 1: remove largest/heaviest waste and add chlorine.
Part 2: pump extra oxygen in to create bacteria that eats waste materials and add purifying chemicals.

44. Septic System Treatment
This is a smaller scale system (few homes, etc).
Waste water flows in
sludge and large particles sink
clean water flows into the ground.

45. Septic System Treatment

46. Water Pollution
Point source pollution: pollution enters water from known sources.
Easy to spot
Laws can stop it
Non-point source pollution: pollution whose source if hard to find.

47. Preventing Pollution Industry/transportation:
Factories can clean pipes
Reuse and recycle chemicals and materials
Inspect and fix vehicles to prevent oil or fuel leaks

48. Preventing Pollution Agriculture
Keep livestock away from streams and lakes
Reduce use of pesticides
Organic farming