Streams (Rivers) Sci 6.1

Runoff: H 2 0 that does not sink into ground Most ends up in streams

How much, depends on terrain + amount of precip. Assume same precipitation for both. Which place would have More runoff?

Assume same precipitation for both. Which place would have More runoff?

Assume same precipitation for both. Which place would have More runoff?

Question 1 1a. What type of terrain would probably have the most runoff? Thick forest, flat meadow, steep slope 1b. What type of terrain would probably have the most runoff? Grassy field, large parking lot, thick woods

People can increase runoff by: Removing vegetation (road building, bad farming, clear cutting)

Clear cut forest in Canada

Building large parking lots/buildings

Silt fence Water retention pond

Question 2 2a. Do plants generally increase or decrease runoff? Increase, decrease 2b. What is a way to decrease runoff? Building roads, building parking lots, building water retention ponds

Extra runoff can lead to: Loss of top soil Aquifers not being replenished (wells going dry) Flooding downstream

Question 3 3a. Too much runoff can cause what? Flooding, less groundwater, less fertile soil, all of the above 3b. Who benefits from excess runoff? Farmers, home owners, wildlife, none of the above

Load: Sediment carried by water Faster moving water carries more load

Question 4 4a. A boulder is more likely to move down a: raging river, calm river 4b. Which could carry more load? A slow stream, a fast stream

3 main types of load: 1.Dissolved: minerals like NaCl 2.Suspended: silt, clay (makes water look muddy) 3.Bed: sand, gravel Bed Dissolved Suspended

Question 5 5a. What type of load is usually close to the bottom of a stream? Bed load, suspended load, dissolved load 5b. What type of load is usually found at every level in a stream? Bed load, suspended load, dissolved load

Types of streams: 1.Meandering streams: on low slopes, fine sediment

Question 6 6a. You’d be more likely to find a meandering stream where? Hilly western NC, flat eastern NC 6b. What’s a synonym for meandering? turning, roaming, wandering, straying, all of the above

Point bar: sediment deposited in slow water

Cut bank: where sediment is carried away in fast water Draw and label fastslow fast slow fast

Oxbow lake: remnant of stream

Question 7 7a. Sediment is deposited on point bars because water is moving relatively: fast, slow 7b. Erosion occurs at cut banks because water is moving relatively: fast, slow

2. Braided streams: bars and islands in middle

3. Mountain stream: steep slope, no floodplain, straighter

Question 8 8a. Rivers follow permanent routes. T/F 8b. A meandering or braided stream flows over what type of terrain? Flat, steep

Drainage basin/Watershed: area drained by a stream

Divide: separates basins Ex.: Rocky Mnts. called Continental Divide

Question 9 9a. Rivers on the western side of the Rockies flow into the: Pacific, Atlantic, Arctic 9b. Rivers on the eastern side of the Rockies flow into the: Pacific, Atlantic, Indian

North Carolina river basins

Question 10 10a. Most of the runoff in Wayne county flows into which river? Cape Fear, Neuse, Tar-Pamlico 10b. A small southern portion of Wayne county is a part of which drainage basin? Cape Fear, Neuse, Tar-Pamlico

Tributary: smaller stream that empties into a larger one

Question 11 11a. Nahunta Swamp Creek eventually flows into the Neuse River. This creek is a ______ of the Neuse River. Contributor, inlet, feeder, tributary 11b. A tributary: takes water away from a larger stream, adds water to a larger stream

Canyon formation: River cuts down as land is uplifted

Uplift of the Colorado Plateaus forced rivers to cut down faster

Question 12 12a. What would have to happen before the Neuse River could make a canyon? The land it runs over would be uplifted, much more rain than normal, an earthquake, a flood 12b. About how long did it take for the Grand Canyon to form? Several thousand years, several million years, several billion years

Stream Deposition: erosion load deposition produces

Question 13 13a. When a stream picks up load it’s called what? Erosion, deposition 13b. When a stream drops load it’s called what? Erosion, deposition, clumsy

Delta: Sediment deposition when stream reaches its base level

Question 14 14a. What happens to the speed of water when it enters a lake or an ocean? Speeds up, slows down 14b. Deltas form from sediment deposition as water flow: decreases, increases

Alluvial fan: deposition when a stream flattens out

Question 15

Stream discharge: Volume of water flowing in m 3 /s (or cfm)

Floodplain: Land next to stream that floods periodically

Question 16

Dealing with floods.

1. Levees: ridges (natural or artificial ) that contain a stream

2. Channelizing: Problems: creating flooding downstream increasing erosion warming water by removing trees Digging to straighten and deepen a stream

Trap river organisms Trap sediment Expensive Flood land upstream 3. Dams:

Question 17