1. Properties of Water

2. Properties of Water
Only natural substance that exists as solid, liquid, and gas in temperatures normally found on Earth
Freezing point = 0oC (32oF)
Boiling point = 100oC (212oF)

3. Properties of Water Expands when it freezes
More dense as a liquid than a solid
Density of water = 1 g/cm3
Density of ice = 0.91 g/cm3

4. Properties of Water High specific heat
A lot of energy is needed to change its temperature.
Moderates air temperature

5. Properties of Water
High surface tension
Cohesion
Adhesion

6. Properties of Water Universal Solvent
Dissolves many (not all) substances

7. The Water Cycle

8. The Water Cycle Earth’s water supply is continuously recycled.
The overall process is powered by the Sun’s energy.

9. Water Storage Ocean Glaciers Lakes Ice/snow Atmosphere
Most water on Earth
Glaciers
Most fresh water
Lakes
Ice/snow
Atmosphere

10. How Water Enters the Atmosphere
Evaporation
Transpiration
Sublimation

11. Forms of Precipitation
Rain
Sleet
Snow
Hail
Freezing Rain

12. The Water Cycle
Once water reaches Earth’s surface as precipitation, it can:
Evaporate
Infiltrate
Run off

13. The Water Cycle

14. Runoff Runoff is water flowing downslope along Earth’s surface.
Runoff may
reach a stream, river, or lake
evaporate
accumulate and eventually seep into the ground (infiltrate)

15. Factors that affect Runoff
Vegetation
Rate of Precipitation
Soil Compaction
Slope

16. Surface Water Movement

17. Watersheds and Divides
all of the land area whose water drains into a stream system
stream system
large river and all its tributaries
Each tributary in a stream system has its own watershed and divides, but they are all part of the larger stream system to which the tributary belongs.

18. NC Watersheds
NC has 12,200 km of rivers and streams

20. Stream Development

21. Moving Water Carves a Path
Must have an adequate supply of water
Stream begins at headwaters

22. Youthful Rivers Steep gradient (slope) Narrow channel (downcutting)
Channel is V-shaped
Fast moving
Moves all sediment sizes
No floodplain
Rapids and waterfalls
More erosion than deposition

23. Youthful River

24. Mature Rivers Channel is U-shaped Medium velocity
Moves many sediment sizes - not boulders
Small floodplain
Meanders begin to form
Erosion and deposition occur
Carries more sediment

25. Mature River

26. Old Rivers Very shallow gradient Channel is wider than deep
Slow moving
Moves small-sized sediments
Wide floodplain
Meanders are abundant
Large discharge

27. Old River

28. Meandering Streams
In a curve, the greatest speed is along the outside of the curve.
Erosion occurs along the outside of the curve.
Deposition occurs along the inside of the curve.

29. Meandering Streams

30. Work of Streams
A stream’s load includes all the materials that the water in a stream carries.
solution (dissolved)
suspension (carried)
bed load (pushed)

31. Work of Streams Erosion
The ability of a stream to erode materials depends on its velocity.
Abrasion
Grinding
Dissolving

32. Lakes and Wetlands

33. Lakes and Freshwater Wetlands
A lake is a depression that collects and holds water.
Reservoirs are lakes made for storing water for a community’s use.

34. Origins of Lakes Natural lakes form in different ways.
Oxbow lakes: streams cut off meanders and leave isolated channels of water.
Lakes can form when stream flow becomes blocked by sediment from landslides.

36. Origins of Lakes Natural lakes form in different ways.
Cirque lakes: depressions left by valley glaciers fill with water.
Kettle lakes: blocks of ice left by melting glaciers melted.
Some lakes are formed when the ceilings of limestone caverns collapse leaving depressions that fill with water.

37. Lakes Undergo Change Lakes are temporary water-holding areas.
Eventually lakes fill in with sediment and become part of a new landscape.

38. Freshwater Wetlands
A wetland is a land area that is covered with water for a large part of the year.
Wetlands include environments commonly known as bogs, marshes, and swamps.

39. Freshwater Wetlands
Bogs receive their water from precipitation and tend to be rich in peat moss.

40. Freshwater Wetlands
Marshes frequently form along the mouths of streams and in areas with extensive deltas.
Marshes have tall grasses.

41. Freshwater Wetlands
Swamps are low-lying areas often located near streams.
Swamps have shrubs and trees.

42. Freshwater Wetlands A filtering system Habitats Pollutants Sediments
Pathogenic bacteria
Habitats
Migratory birds
Water birds
Endangered species

43. Freshwater Wetlands
From the late 1700s to the mid 1980s, the continental United States lost 50 percent of its wetlands.