8. Fluvial Processes and Landforms

Question 1

what is the most widespread and geomorphic agent on land.

Answer 1

rivers

They occur in diverse environments, even in deserts

Question 2

The river channel is formed when

Answer 2

surface run-off is concentrated into a long depression

Question 3

Tiny rills and larger masses of sheet flow coalesce to form

Answer 3

The channel
The width and depth of the channel vary along its
course

Question 4

As the water flows downhill under gravity seeking sea level or its base level, the channel reflects what?

Answer 4

the fluvial processes

Question 5

a drainage basin is

Answer 5

an area of land drained by a river and its tributaries

Question 6

A drainage basin boundary is marked by?

Answer 6

a ridge of high land beyond which any precipitation will drain into adjacent basins.

This boundary is called a watershed

Question 7

watershed (drainage basin) is the

Answer 7

The land from that delivers surface water, sediment and dissolved substances into a particular river, lake, wetland, or other body of water.

Question 8

A drainage basin may be described as what type of system?

Answer 8

a open system

Question 9

If a drainage basin is viewed as a system then its characteristics are

Answer 9

inputs in the form of precipitation (rain and snow)

outputs where the water is lost from the system either by the river carrying it to the sea or through evapotranspiration

Within this system,
some of the water is stored;
in lakes and/ or in the soil, or
passes through a series of transfers or flows,
e.g. infiltration, percolation, throughflow

Question 10

evapotranspiration is

Answer 10

the loss of water directly from the ground, water surfaces and vegetation

Question 11

figure3.1 The drainage basin as an-open system

Answer 11

chegg

Question 12

the greater the intensity of a storm

Answer 12

the shorter its duration

Convectional thunderstorms are short, heavy and may be confined to small areas,

whereas the passing of a warm front of a depression will give a longer period of more steady rainfall extending over the entire basin

Question 13

Evaporation is

Answer 13

the physical process by which moisture is lost directly into the atmosphere from water surfaces, including vegetation and the soil, due to the effects of air movement and the sun’s heat

Question 14

Transpiration is a

Answer 14

biological process by which water is lost from a plant through stomata in its leaves

Question 15

Evaporation rates are affected by what?

Answer 15

temperature
wind speed
humidity
hours of sunshine and other climatic factors

Question 16

Transpiration rates depend on

Answer 16

the time of year

the type and amount of vegetation

the availability of moisture and

the length of the growing season

Question 17

example of how it is possible to distinguish between the potential and the actual evaporation spiration of an area

Answer 17

in deserts there is a high potential evapotranspiration because the amount of moisture that could be lost is greater than the amount of water actually available

On the other hand, in Britain the amount of water available for evapotranspiration nearly always exceeds the amount which actually takes place

hence the term actual evapotranspiration

Question 18

transpiration is limited by

Answer 18

the availability of water in the soil

Question 19

Interception storage is

Answer 19

The first set of precipitation that falls on the vegetation surfaces (canopy) or human-made cover and is temporarily stored on these surfaces which shelters the underlying ground

Intercepted water either can be evaporated directly to the atmosphere, absorbed by the canopy surfaces or ultimately transmitted to the ground surface.

Question 20

interception storage is greater where?

Answer 20

is greater in a woodland area or where tree crops are grown

than on grass or arable land