Chapter 12 River Systems

Question 1

Erosion

Answer 1

Movement of soil and dirt from water, wind, and ice.

Question 2

Deposition

Answer 2

Long distance relocation of rock material that has been removed.

Question 3

Rills

Answer 3

Very small channel created from surface runoff.

Parallel rills form on steep slopes.

Question 4

Alluvium

Answer 4

Rock material deposited by streams. Streams/rivers transport alluvium to oceans/lake

Question 5

Sacramento River

Answer 5

Largest river in California
From the Clamammoth Mountains to San Joaquin Delta 445 miles long.
Provides over 1/2 of water to California’s population
Known as the “Nile of the West”
Discovery Park is the confluence of the American river and Sacramento river.

Question 6

American River

Answer 6

Flows from the Sierra Nevada to Folsom Lake

Main source of drinking water

Question 7

Rivers

Answer 7

Large stream

Question 8

Channnels

Answer 8

Streams and rivers flow into depressions

Question 9

Gradient

Answer 9

The steepness of a stream channel. Steeper near the source, gentler near the mouth

Question 10

Drainage Patterns:

Dendritic

Answer 10

Most common drainage pattern is tree like

Question 11

Drainage Patterns:

Trellis

Answer 11

Indicates parallel folding or inclined rock layers

Question 12

Drainage Patterns:

Radial

Answer 12

Indicates a conical mountain or hill

Question 13

Drainage Patterns:

Parallel

Answer 13

Indicates steep slopes

Question 14

Drainage Patterns:

Rectangular

Answer 14

Indicates jointing or faulting

Question 15

Braided Stream

Answer 15

Stream divided into multiple threads by bars of coarse alluvium. Located on valley floors

Question 16

Alluvial Fan

Answer 16

The fan shape results from multiple storms
Braided stream patterns develop
Located in deserts

Question 17

Delta

Answer 17

Accumulation of alluvium formed where a river empties into an ocean or lake
Local Example: Sac-San Joaquin Delta

Question 18

Estuary

Answer 18

Water body at river’s mouth where freshwater meets seawater

Question 19

Meandering Streams

Answer 19

Widely curved stream channel

Example: Sacramento’s Greenhaven/Pocket Area

Question 20

Oxbow Lake

Answer 20

A lake in an abandoned meander

Question 21

Nickpoint

Answer 21

An abrupt change in stream gradient. Waterfalls occur at nickpoint

Question 22

Flood

Answer 22

Occur when streams overflow their channels

Question 23

Flash flood

Answer 23

Occur in smaller watershed with steep gradients

Question 24

Natural Levees

Answer 24

Formed from flooding

Question 25

Artificial Levees

Answer 25

Embankments build on top of natural levees

Example: American River Bike Trail Levees

Question 26

Natomas Basin

Answer 26

54,000 acre basin
42 mile ring of levees
Flood zone designation changed after Hurricane Katrina; bldg moratorium in 2008
US Army Corps of Engineers/SAFCA upgraded levees; 2015 bldg moratorium lifted

Question 27

When is flooding is more likely to occur?

Answer 27

High rainfall and high water table

Question 28

Which of the following is not used for flood control in Sacramento Area?

Answer 28

The Tower Bridge