Chapter 8

Question 1

Overland flow

Answer 1

water that travels as unconfined sheets

Question 2

Stream flow

Answer 2

Water that travels in confined channels

Question 3

Groundwater

Answer 3

Soaked-in water that is present at the surface of the Geosphere

Question 4

Base flow

Answer 4

Component of water, that initially soaks in to the ground and enters a stream through its base

Question 5

Channel Gradients

Answer 5

Measured as metres per kilometre gradients.

Question 6

Sinuous flow

Answer 6

Many bends causes it to flow fastest on the outside curve of each bend and more slowly on the inside curve

Question 7

Discharge

Answer 7

The amount of water that flows through a stream. m3/second

Question 8

Hydrographs

Answer 8

Graphs of river discharge at one point in a stream, plotted against time, typically over periods of one to many years.

Question 9

Tributaries

Answer 9

Smaller streams that flow into larger rivers

Question 10

Drainage basin

Answer 10

The area drained by a major river and its tributaries

Question 11

Downcutting

Answer 11

Lowering of the floor of the channel as material is eroded

Question 12

Slot canyon

Answer 12

a valley with almost vertical sides usually with rocks of the side

Question 13

Mass wasting

Answer 13

Gravity-driven process that bring material down valley sides into the channel

Question 14

Scree or talus

Answer 14

Fallen rock material may accumulate at the base of a steep slope.

Question 15

Slides

Answer 15

Coherent masses of rock or soil, that move above distinct failure surface.

Question 16

Translational slide

Answer 16

Failure surface is approximately planar.

Question 17

Rotational slide

Answer 17

Failure surface is curved. Upper surface of the moved material is tilted inwards, toward the failure surface.

Question 18

Flows

Answer 18

Masses in which the moving material loses coherence as it moves, behaving more like a liquid

Question 19

Slumps

Answer 19

Material moves down slope in a slide it may become progressively more disrupted.

Question 20

Laminar

Answer 20

All material is transported roughly parallel to the base of the flow

Question 21

Turbulent

Answer 21

material is carried by swirling movements in the flow, but deposits of debris flow are typically poorly sorted.

Question 22

Creep

Answer 22

Slow movements, occur on slopes where they are promoted by changes in the amount of water in the soil.

Question 23

Solifluction

Answer 23

When ice melts, the grains settle more vertically downwards

Question 24

Headward erosion

Answer 24

Rapidly downcutting streams oversteepen the region around their headwaters, causing their valleys to extend in an upstream direction

Question 25

River Capture or piracy

Answer 25

Headward erosion may cause one stream to cut into another’s valley, eventually diverting the water in the process

Question 26

Lateral erosion

Answer 26

Rivers with low gradients carry out erosion by widening their valleys, rather than deepening them.

Question 27

Floodplain

Answer 27

Lateral erosion gradually pushes out the sides of the valley

Question 28

Alluvial fan

Answer 28

dumping of large amounts of sediment at a break in slope, forming multiple distributaries.

Question 29

Fluvial

Answer 29

Sediments deposited by rivers

Question 30

Braided systems

Answer 30

Multiple channels that branch and rejoin repeatedly downstream

Question 31

Meandering Systems

Answer 31

Later erosion causes a single channel to migrate sometimes across a broad valley

Question 32

Point-bar

Answer 32

Deposition, typically of sand, occurs on the inside of the curve where the current is slower

Question 33

Ox-bow lake

Answer 33

Isolated meander channel

Question 34

Natural levee

Answer 34

Rapid deposition at the edge of a channel may deposit a raised bank.

Question 35

Terraces

Answer 35

Flat areas part-way up the valley sides

Question 36

Lakes

Answer 36

Standing body of water filling a depression on land

Question 37

Open Lakes

Answer 37

Lakes which have an outlet with discharge comparable to the inflow that provides water to the lake.

Question 38

Closed lakes

Answer 38

Have an inlet stream but no outlet stream. Water is reduced by evaporation. Arid climates