1. Warmup How many river basins are in North Carolina?
Which two river basins border Durham?
Write two facts about your river basin from Friday.
Which direction does water flow?

2. 2.3.2bc Rivers, Aquifers, and Floods
Explain river systems including NC river basins, aquifers, and watersheds.
Explain how flood events might be affected by groundwater levels.

3. Surface Water and Ground Water
Groundwater and surface water have a reciprocal relationship, regularly feeding each other. Most streams and rivers get about half their volume from groundwater.
Source: The Water Connection

4. Floods
During a flood, surplus surface water helps recharge groundwater.

5. Flood and Flood Control
A flood occurs when the discharge of a stream becomes so great that it exceeds the capacity of its channel and overflows its banks.
Measures to control flooding include artificial levees, flood control dams, and placing limits on floodplain development

6. Drainage Basins
A drainage basin is the land area that contributes water to a stream.
A divide is an imaginary line that separates the drainage basins of one stream from another.

7. Flooding What are some things that cause flooding? Heavy Rain
Rapid Spring Snowmelt
Why are floods bad?
They cause damage
They can come without warning (flash floods)
They can hurt people
Cost a lot of money
What are some floods that you have heard of, why were they dangerous? –

8. Flooding There are several methods used to help prevent flooding:
Artificial levees
Create Dams
Sandbags
Limit construction around areas known to flood
Mississippi Flooding
What caused the flood?
What caused the most damage
during the Flood?

9. Floods
Lots of water = landslides too

10. Path of a drop of water…
Remember: A drop of water can either infiltrate into the ground (groundwater) or runoff the surface into a river or stream

11. Drainage System Are pattern formed by streams, rivers, and lakes
They depend on
Topography of the land (landforms)
How hard or soft the rock is
The gradient of the land (how steep it is)
They are divided from each other by topographic barriers (mountains/high points) to form a watershed.

12. Rivers Flow of a river or stream is due to GRAVITY.
Speed at which it flows is due to discharge (volume rate of water flow; or how much water is passing by) is measured by:
Width x Depth x Velocity

13. Aquifers
An aquifer is underground soil and/or rock through which water can easily move.
Groundwater is stored in aquifers

14. Aquifers Unconfined aquifer Confined aquifer
Has no barrier between its top layer and the surface of the ground
Water level rises and drops in response to precipitation infiltrating directly above
Confined aquifer
Sandwiched between two largely impenetrable layers (clay, shale, etc)
Recharges more slowly due to limited number of places through which rainfall can enter

15. Aquifers of NC

16. River basin activity One color: Another color:
Trace highest points (divide of river basin)
Another color:
Trace lowest points (drainage pattern of river system)
Transfer/re-draw boundaries of river basin and drainage pattern on a separate piece of paper.
Turn in w/group member names.