2. Surface Water

3. Surface water notes: Where is all the water? 97.5% in Oceans
1.8 % in Ice
.63% in groundwater
.007% in salty lakes and streams
.009% in fresh water lakes and streams
.0001% in the atmosphere

4. Where is all the fresh water?
73.9% in ice
25.7% in groundwater
.36% in freshwater lakes and streams
.04% in the atmosphere

5. What happens to water when it rains?
It either infiltrates (soaks) into the ground or
It remains on the surface

6. Watersheds Its an area that drains to a stream
Watershed boundaries or divides are high places
First order streams have small watersheds 2.5 km
Mississippi River basin is a tenth order stream. It drains 320 million sq. miles

7. Chesapeake Bay Watershed
Surface Water
James River
York River
Potomac River
Susquehanna River
Rappahannock River
All of the rivers listed above
drain into the:
Chesapeake Bay Watershed

8. Label your River diagram in your notes
Drainage Divide
Meander
Flood Plain

9. Streams are constantly changing?
Young streams flow straight, smaller, have rapids, faster
Mature streams meander or curve
Old streams are widest, carry the most water, slower

10. Young River Characterized by: _________
Slope: (steep, moderate, or gentle?)
Velocity: (slow, moderate, or fast?)
Erosion rate: (slow, moderate, or fast?)

11. Mature River Characterized by: _________
Slope: (steep, moderate, or gentle?)
Velocity: (slow, moderate, or fast?)
Erosion rate: (slow, moderate, or fast?)

12. Old River Old River Characterized by: _________
Slope: (steep, moderate, or gentle?)
Velocity: (slow, moderate, or fast?)
Erosion rate: (slow, moderate, or fast?)
Old River

13. Meanders: Curves in Rivers
Cut Bank- where the bank is eroding away, faster moving water
Meanders: Curves in Rivers
Point Bar- the inside of the curve where sediment is being deposited. Slower water with less velocity.
Cut Bank up close

14. How Rivers become straight again?
A meander forms
Over time, the meander gets curvier
It gets so curvy that the two cut banks meet each other
Eventually none of the water goes around the meander anymore
The leftover lake is an Oxbow Lake

15. What is a flood plain?

16. Floodplains
Flat or gently sloped region around the river, in which the river flows during flooding
The larger the river, the bigger the flood plain
Deltas: Flood plains at the mouths of rivers are known as deltas
Alluvial fans form when rivers drop the soil at the base of the mountain.

17. Rivers carry sediment
Three types of loads
bed load at bottom include sand, gravel, & pebbles,
suspended loads in the middle include clay and silt
solution includes dissolved materials
The faster the velocity of the water, the greater the load (MORE EROSION!!!)

18. Factors that influence flooding
Rainfall amounts
Topography
Type of Soil
how permeable
how saturated
Amount of Impermeable land area
Vegetation
A 10 year flood may occur once every ten years or has a 1/10 (10%) chance of occurring yearly

19. Glaciers carve U- shaped valleys
riVers carve V-shaped Valleys

20. Flood Frequency Curves R= N+1/r
Are we at risk for flooding?