1. Surface Water
Chapter 6

2. Water Cycle

3. 6.1 Streams and Rivers River Systems (structure)
Tributary- a stream that runs into another stream or river
River system- a river and all of its tributaries
Drainage basin, or watershed- all the land that drains into the river either directly or through its tributaries
Mississippi River system
Divide- high land that separates one drainage basin from another
Continental Divide in the Rocky Mtns

4. Headwaters/Source- beginning of stream or river
Mouth- end of the stream or river where it enters into another body of water

5. Characteristics
Velocity- distance that water travels in a given amount of time
Related to the amount of energy that the water has
Erosion occurs more quickly
Other characteristics affect the velocity
Gradient- steepness of the slope of a stream or river
Steep at its source; gradual at sea level

6. Characteristics cont…
Discharge- the amount, or volume, of water that passes a certain point in a given amount of time
Not constant over length of a river
Increases downstream as tributaries add more water
Not constant year-round- increased precipitation/melting snow
Channel- the path through which the water flows in a stream or river
Shallow, winding stream with many boulders has contact with surface area that causes it to slow down by friction
Straight channel that is wide and deep has less surface area in contact with water, so velocity is greater

7. 6.2 Stream Erosion and Deposition
Deposition- the process by which materials are deposited
Occurs because the river or stream no longer has enough energy to transport them
Erosion by rivers
Running water wears down Earth’s surface by breaking up bedrock and by removing eroded rock and soil materials
Breaks up materials by mechanical means
Abrasion mainly; in time, creates rounded boulders, pebbles, and sand grains from the cutting tools

8. Transported Material (Load)
Dissolved Substances- smallest particles are dissolved
Suspension- a state in which rock materials carried by a river are stirred up and kept from sinking by the turbulence of stream flow
Bedload- sand, pebbles, and boulders that are moved along the bed of a stream and that are too heavy to be carried in suspension

9. Transporting Materials
Two measures are used to describe the ability of a stream to transport materials
Competence- a measure that describes the maximum size of the particles a stream can carry
Capacity- a measure of the total amount of sediment a stream can carry
Depend on the velocity and discharge
Vary along a stream and change throughout the year
High velocity + High discharge = large amount of sediment and larger sizes of sediment particles

10. Depositional Features
Delta- a fan-shaped deposit that forms when a river flows into a quiet or large body of water
River water comes to almost a standstill at a delta
Distributaries- branches formed by rivers flowing over its delta
Responsible for delta’s shape
Formation is delicate balance between deposition and erosion

11. Stream Valleys Narrow valleys Wide valleys
narrow V-shaped valley shows that the stream’s primary work has been downcutting toward base level
Features: Rapids and waterfalls
Wide valleys
Downward erosion is less dominant
More energy is directed side to side
Floodplain- the flat, low-lying portion of a stream valley subject to periodic flooding

12. Floodplains Streams that flow on floodplains move in meanders
Cutoffs- shorter channel segments
Oxbow lakes- abandoned bend of a river/stream

14. Floods
Most caused by rapid spring snow melt or storms that bring heavy rains over a large region
Ex: Mississippi River in 1993
Measures to control flooding
Artificial Levees- earthen mounds built on the banks of the river
Flood-control dam- store floodwater and then let it out slowly
Limits on floodplain development- minimizing the development on floodplains

15. 6.3 Water Beneath the Surface
Much of the water in soil seeps downward until it reaches the zone of saturation
The area where water fills all of the open spaces in sediment and rock
Groundwater is the water within this zone
Water table- upper limit of zone of saturation
Zone of aeration- area above water table where the soil, sediment, and rock are not saturated

16. Groundwater

17. Movement
Porosity- the percentage of the total volume of rock or sediment that consists of
pore spaces
Permeability- the ability to release a fluid
Aquitards- impermeable layers that get in the way or prevent water movement
Aquifers- permeable rock layers or sediments that transmit groundwater freely

18. Springs
A flow of groundwater that emerges naturally at the ground surface
Forms whenever the water table intersects the ground surface
Hot springs
6°C - 9°C warmer than average annual temperature
Source of heat is cooling igneous rock
Geysers
Intermittent hot spring or fountain in which a column of water shoots up with great force at various intervals

19. Below: Old Faithful Geyser Eruption
Above: Geyser formation

20. Wells Hole bored into the zone of saturation
Irrigation for agriculture
Industrial use
Home use
Cone of depression- feature formed when too much water is being drawn out in a short period of time
Artesian well- any formation in which groundwater rises on its own under pressure
water must be in an aquifer that is tilted so that one end is exposed at the surface
Must be aquitards both above and below the aquifer to stop the water from escaping

21. Artesian Well

22. Karst Topography
Karst topography- landscapes that have been shaped largely by the dissolving power of groundwater
Typically have irregular terrain, with many depressions
Sinkholes- depression produced in a region where groundwater has removed soluble rock
Form in one of two ways
Gradually develop; fairly shallow and have gentle slopes
Form when roof of cavern collapses; steep-sided and deep

23. Sinkholes South Florida Karst Virtual Field Trip
FLORIDA ATLANTIC UNIVERSITY
Department of Geosciences
South Florida Karst Virtual Field Trip
Introduction
Miami Oolite
Karst Definitions
Karst Links
S. Florida Karst Sites
Acknowledgements
Sinkholes
Source: 
Source: 

24. Environmental Problems
Overuse and contamination
threatens groundwater supplies in
some areas
Nonrenewable resources
Subsidence- ground level sinks
Contamination
Septic tanks, farm wastes, inadequate or
broken sewers
Fertilizers, pesticides, highway salts
Cleanup
Abandoning water supply
Pumping and treatment

25. SALT WATER INTRUSION What’s going on here?
Ever noticed this at the beach?
Man… that shower was salty!! (and the tap water, too!!!)
So… what is this caused by again?
Aquifer depletion!
And what else is caused by this???
Sinkholes!

26. Contamination