Chapter 16

Question 1

Overland flow

Answer 1

unchanneled downslope movement of water

Question 2

Streamflow

Answer 2

chaneled movement of water

Question 3

valleys

Answer 3

portion of terrain in which a drainage system is established

Question 4

interfluve

Answer 4

higher land above valley walls that separates adjacent valleys

Question 5

drainage basins

Answer 5

areas that drain to the valley; watersheds; drainage divide

Question 6

stream order

Answer 6

smaller streams join larger ones; smaller numbers are more frequent; larger numbers are longer streams

Question 7

Stream competence and capacity

Answer 7

stream competence: measures maximum particle size a stream can transport
stream capacity: measures the amount of solid material a stream can transport

Question 8

erosion by streamflow

Answer 8

once channeled, erosion is enhanced; erosion increased by debris; streamflow picks up; chemical weathering—corrosion

Question 9

straight channels

Answer 9

short and indicative of strong geologic structure control

Question 10

sinuous channels

Answer 10

irregular and gentle curvature

Question 11

meandering channels

Answer 11

highly variable curvature

Question 12

braided streams

Answer 12

multiple interwoven channels separated by loose bars or islands

Question 13

dendric pattern

Answer 13

treelike pattern with random merging of streams

Question 14

trellis pattern

Answer 14

forms in areas of hard and soft bedrock in close content; shape modified by structure of bedrock

Question 15

radial pattern

Answer 15

streams descend in a concentric uplift (like a volcano)

Question 16

centripetal pattern

Answer 16

streams converge into a uniform basin (like a 2D funnel)

Question 17

valley deepening–downcutting

Answer 17

hydraulic power of moving water to lower the streambed

Question 18

valley deepening–base level

Answer 18

lower limit to the amount of downcutting can occur–base level is sea level

Question 19

valley deepening–knickpoints

Answer 19

channel irregularities such as rapids and waterfalls

Question 20

valley widening

Answer 20

widening slows above base level; as gradient decreases, stream flow meanders and lateral erosion occurs; fastest on outside of curves (cut bank); slowest water on inside of curve accumulates alluvium (point bar)

Question 21

floodplains

Answer 21

humans live on these; flat land, abundant water, productive soil

Question 22

delta formation

Answer 22

slowed flow when it reaches an ocean or lake results in deposited sediment; this debris builds up and forms a delta

Question 23

deposition valleys cause

Answer 23

aggradation

Question 24

evolution of a cutoff meander

Answer 24

erosion, cutoff meander, oxbow lake, meander scar