1. Water Resources in NC

2. What does Water Balance Mean?
Precipitation equals Evaporation

3. Water Cycle
Water is constantly moving among the oceans, the atmosphere, the solid Earth, and the biosphere.
Link to Water Cycle

4. Parts of the water cycle
Evaporation – water changes into vapor into the air
Precipitation – liquid or solid water from the clouds
Infiltration – water moving through the ground
Transpiration – water released from plants
Runoff – when flash rain storm hits the ground and is not absorbed.

5. Water Facts of Life
There is the same amount of water on Earth as there was when the Earth was formed. The water from your faucet could contain molecules that dinosaurs drank.
75% of the human brain is water and 75% of a living tree is water.
A person can live about a month without food, but only about a week without water.
The average total home water use for each person in the U.S. is about 50 gallons a day.
Water expands by 9% when it freezes. Frozen water (ice) is lighter than water, which is why ice floats in water.

6. Water Supply in the World

7. Distribution of the Water on Earth
71% of Earth is water
97% in the oceans
3% is freshwater
2% in ice and glaciers
0.6% in underground water
0.4% in rivers, streams, lakes and atmosphere

8. Water Supply & Use

9. How is water used? 70% - Irrigation 20% - Industry
10% - Cities & Residence

10. Oceans currents

11. Ocean circulation also influences climate
Ocean circulation: ocean water exchanges heat in the water with the atmosphere
Thermohaline circulation: a worldwide current system in the ocean.
Warmer, fresher water moves along the surface and carries heat to Europe
North American Deep Water (NADW): the deep portion of the thermohaline circulation
denser, saltier, cool water that sinks
moves deep beneath the surface

12. NADW is vulnerable
If Greenland’s ice melts, freshwater runoff would dilute surface waters, making them less dense, and stopping NADW. – This has occurred in the past

13. Ocean Currents Primary Forces--start the water moving
Solar Heating
Winds
Gravity
Coriolis
Secondary Forces--influence where the currents flow

14. Warm and Cold Currents
Warm ocean currents: warm water from tropics to poles.
Cold ocean currents: cold water poles toward the equator.
The Gulf Stream, is a warm-water current that moves up the Eastern coast of the United States

15. Fresh Water supply

16. Water Facts
The primary use for fresh water in U.S. is for agriculture.
In our homes, we use the most fresh water to wash, clean and flush.
The typical person in an industrialized nation uses gallons per week!

17. Groundwater

18. Groundwater
50% of the water used by the public is pulled from groundwater
Most people who live in the county use groundwater
Groundwater link

19. Movement of water underground
Porosity: percentage of pore spaces showing how much water is stored
Permeability: water can pass through connected pore spaces
Clay: smallest amount of pore space of any soil type – not permeable

20. Groundwater
Zone of aeration: area above the water table where water passes through
The water table: the upper level of the Zone of Saturation
Zone of saturation: area where the soil, sediments and rock are saturated with water.
Groundwater: the water within the Zone of Saturation

21. Ground Water
Aquifer : underground layer of water-bearing permeable rock (gravel, sand or silt) from which ground water can be extracted using a well.
A cone of depression occurs in an aquifer when a lot of ground water is pumped from a well.

22. Artesian well: groundwater rises on its own under pressure
Pumping can cause the water table to be lower

23. Problems with Groundwater
Withdrawing water for agriculture
Heavy metals contaminating the water (arsenic, cadmium, lead)
Salt water intrusion (salt water from ocean enters the groundwater)

24. Caverns Sinkholes form near the surface causing depressions
A cavern is a naturally formed underground chamber when water is withdrawn leaving it empty.
Erosion forms most caverns at or below the water table
Sinkholes form near the surface causing depressions
Watershed Link

25. Rivers

26. A stream’s profile Headwater (mountains) Mouth (oceans)
at the beginning of a stream Temperatures are cooler
Higher Dissolved Oxygen
Fish found: trout
Mouth (oceans)
at the end of a stream
Murky waters
Lower Dissolved Oxygen
Fish found: catfish and carp

27. Watershed
An area of land that contains a common set of streams and rivers
Tributary: a stream that empties into another stream

28. Drainage Basins
A drainage basin is the land area that contributes water to a stream

29. Base level Meandering Stream Temporary or local base levels
Lowest point to which a stream can erode
Ultimate base level is sea level
Temporary or local base levels
lakes
main streams
Meandering Stream
Slow moving stream located in the flat regions or territory

30. Erosion Problems and Flooding

31. Three ways streams erode channels
Abrasion
Grinding
Dissolving soluble material

32. Controlling Floods
Natural levee parallels a stream and helps to contain its waters, except during flood stage

33. Controlling Floods Artificial Levees
Concrete mounds are built on the banks of a river, increasing the amount of water it can hold.

34. Results of Floods Floodplains – areas where water floods the land
Provides a supplement of nutrient-rich silt to floodplain areas
Recharge groundwater
Kill and causes property damage

35. Human activities causing Flooding
removing vegetation
logging
overgrazing
forest fires
mining
destruction of wetlands
building on floodplains
urbanization

36. Drought

37. 41% of people live in river basins that do not have enough fresh water!
Dry climate
Drought
Too many people using and wasting water
Lack of money to drill deep wells and build storage

38. Causes of a Decrease in Available Water
Dry climate
Drought - a period in which precipitation is much lower and evaporation is much higher
Desiccation - drying of soil because of such activities as deforestation and overgrazing
Water stress - low per capita availability of water caused by overpopulation