Rivers Definitions

Question 1

Precipitation

Answer 1

any form of water(eg. dew, fog, frost, hail, mist, sleet, snow, etc.) falling on the Earth’s surface from the atmosphere

Question 2

Discharge

Answer 2

the amount of water flowing across the width of a river at any given point

Question 3

Drainage basin

Answer 3

the area of land drained by a river and its tributaries(streams)

Question 4

Watershed

Answer 4

the boundary of a drainage basin

Question 5

Evaporation

Answer 5

the change of water(liquid) into water vapour(gas) in a water body

Question 6

Transpiration

Answer 6

the loss of water in the form of water vapour through the stomata of plants

Question 7

Evapotranspiration

Answer 7

the loss of water in the form of water vapour through plants and in water bodies

Question 8

Condensation

Answer 8

the change of water vapour(gas) back into water(liquid)

Question 9

Infiltration

Answer 9

the movement of water into the ground from the surface

Question 10

Percolation

Answer 10

the movement of water through the soil itself

Question 11

Overland flow

Answer 11

the movement of water over the land

Question 12

Through-flow

Answer 12

the flow of water under permeable ground

Question 13

Groundwater flow

Answer 13

the movement of water underground(below the soil)

Question 14

Saturated

Answer 14

full of water

Question 15

Permeable

Answer 15

capable of soaking up water

Question 16

Wetted perimeter

Answer 16

length of the wet part of the channel’s cross-section containing flowing water

Question 17

Velocity

Answer 17

the speed at which the river is flowing

Question 18

Erosion

Answer 18

the wearing away and removal of rocks through the action of the agents of erosion(wind, water, ice and gravity)

Question 19

Deposition

Answer 19

the laying down of solid material(eg.mud, sand, etc.) on the seafloor and river or lake beds

Question 20

Network

Answer 20

a collection of all the paths formed by every tributary of the river in its drainage basin

Question 21

Tributaries

Answer 21

streams that feed into a larger stream, river or other water body

Question 22

Source

Answer 22

the original point from which the river flows

Question 23

Confluence

Answer 23

the point at which two rivers meet

Question 24

Interception

Answer 24

the process of interrupting the movement of water in the water cycle leading to water bodies(or the ground)

Question 25

Capacity

Answer 25

the total amount of sediment or load that a stream or river can carry at any one time

Question 26

Competence

Answer 26

the maximum size of a particle that a stream or river can carry

Question 27

Flood plain

Answer 27

an area next to a river that would be affected by flooding if the river overflowed its banks

Question 28

Distributaries

Answer 28

a stream or river channel resulting from the division of a larger stream channel(often found in deltas)

Question 29

Delta

Answer 29

a landform(often triangular in shape) which develops where a river meets a slow body of moving water such as a lake or ocean(sediment builds up above the water level forcing the river to split into distributaries to form a delta)

Question 30

Levée

Answer 30

a natural or artificial wall that blocks water from going to certain areas

Question 31

Gorge

Answer 31

a deep, narrow valley with steep, rocky sides often with a stream or river flowing through it

Question 32

Vertical erosion

Answer 32

the process in which a stream or river flowing quickly down a steep gradient in an upland area wears away the bed at a faster rate than the valley sides, leading to a V-shaped valley

Question 33

Lateral erosion

Answer 33

the process in which a stream or river wears away the sides and banks on each side of the channel

Question 34

Hydrograph

Answer 34

a graph which shows the pattern of a river's discharge(measured in cubic centimetres per second(cumecs) over a period of time)

Question 35

Hydraulic action

Answer 35

the process by which the force and impact of flowing water removes material from the bed and banks of a river

Question 36

Corrasion/Abrasion

Answer 36

the effect of the load grinding away at the bed and banks of a river like sandpaper(the most effective process of river erosion)

Question 37

Attrition

Answer 37

the process in which material such as rocks or stones carried by waves hit and knock against each other, wearing them down, and resulting in them becoming smaller and more rounded

Question 38

Solution/Corrosion

Answer 38

the process in which some rocks are dissolved in the presence of water in the river

Question 39

Load

Answer 39

the material carried by a river

Question 40

Solution load

Answer 40

the materials/minerals that are dissolved in the river and carried through it

Question 41

Suspension load

Answer 41

the very light materials that are carried near the surface of the river(giving it its colour)

Question 42

Saltation load

Answer 42

the small pebbles and stones that are bounced along the riverbed

Question 43

Traction load

Answer 43

the heavy boulders and rocks that are rolled along the riverbed(this takes the most energy)

Question 44

Plunge pool

Answer 44

a deep depression in a riverbed at the base of a waterfall which is formed by erosion

Question 45

Interlocking spurs

Answer 45

a series of ridge-like projections which protrude out on alternate sides of a V-shaped valley around which a river winds its course

Question 46

Meander

Answer 46

a bend in a river channel

Question 47

Oxbow lake

Answer 47

a U-shaped lake that is formed when a wide meander of a river is cut off, creating a free-standing body of water

Question 48

Base flow

Answer 48

the low level of water that is always in the river throughout the year

Question 49

Peak discharge

Answer 49

the maximum amount of water in the river due to rainfall

Question 50

Bankful discharge

Answer 50

the maximum amount of water in the river just before it is about to flood over its banks

Question 51

Time lag

Answer 51

the time between the peak rainfall and the peak discharge

Question 52

Hard engineering

Answer 52

the construction of costly, permanent structures that will affect river flow, prevent the damage caused by floodwater, or even prevent the flooding completely

Question 53

Soft engineering

Answer 53

the use of relatively cheap methods or structures that work with the river and do not involve permanent structures or lots of construction

Question 54

Dredging

Answer 54

the process of clearing the bottom of a riverbed by removing material(eg. weeds, silt) from it