Rivers

Question 1

Water Cycle

Answer 1

Evaporation is the process by which a liquid is converted into vapour.
Transpiration is the process by which plants lose water through their leaves. Water vapour escapes through tiny openings called stomata in the leaves.
Condensation is the process by which vapour is converted into a liquid. In the diagram it refers to water vapour being converted into water droplets in the atmosphere.
Precipitation refers to any of the forms in which water falls from the atmosphere and reaches the ground including rain, snow or hail.
Infiltration is the process by which water enters the soil.

Question 2

Definition of rivers

Answer 2

A river is a fairly large body of water which flows in a channel and through which excess water is drained away from the land

Question 3

Drainage Basin

Answer 3

is the area drained by a river and its tributaries.

Question 4

Drainage Patterns

Answer 4

Dendritic- develops in gently sloping basins with uniformed rock type. Streams flow into each o
Trellised- occurs when there are alternate bands of hard and soft rock, joining the main river at right angles.
Radial- rivers radiate outward in all directions from a high central point of dome.

Question 5

How does a river erode?

Answer 5

Corrasion
attrition
solution
hydraulic action

Question 6

Definition of corrasion

Answer 6

As the river flows it grinds its load against its bed and banks. This loosens material which the rivers carries downstream.

Question 7

Definition of attrition

Answer 7

the process by which material being carried by the river, such as rocks and stones, collide with each other. Over time, they become smaller and smaller. They also become smooth and rounded.

Question 8

Definition of solution

Answer 8

Some minerals in rocks and soil are soluble. They are slowly dissolved by river water as it comes into contact with them. Examples of such minerals are salt and calcium carbonate.

Question 9

Hydraulic Action

Answer 9

This refers to the force of the water itself. Water splashes against river banks and forces it way into cracks and openings. This loosens material along the bed and banks and the river carries this material away

Question 10

Transportational process

Answer 10

Heavy materials transported along the river
some materials are such as gravel and pebbles roll, slide or are dragged along the river bed.- traction
sand sized particles, hop along the bed- saltation
lighter materials comprise the sediment of a river
very fine materials like clay and sediment are transported in suspension.
Limestone and chalk are soluble in carbonic acid and are transported in solution.

Question 11

Stages of a river’s course

Answer 11

-upper course or youthful stage
-middle course or mature stage
-lower course or old age

Question 12

upper course

Answer 12

valley slides are steep with a narrow v-shaped section
the river flows around spurs
vertical corrasion or down cutting is dominant
features- waterfalls, potholes, interlocking spurs

Question 13

middle course

Answer 13

-the valley has a wide”v” shape
-the valley floor is wide
-gradient varies from 1 to 10 to 1 in 100.
features-meanders, river cliffs

Question 14

v-shaped valley

Answer 14

the river contains large boulders which can erode the bed rapidly when the river is in flood. This results in the river cutting downward into its bed forming steep v-shaped valleys

Question 15

Meander

Answer 15

is a sweeping bend in a river.

Question 16

ox-bow lakes

Answer 16

ox-bow lakes are horseshoe shaped lakes that are found on river floodplains close to a meandering river.

Question 17

Braided

Answer 17

a braided channel is one that is divided into smaller channels by temporary islands called eyots.

Question 18

Floodplains

Answer 18

floodplains are large,flat expenses of land that form on either side of a river.

Question 19

Waterfalls

Answer 19

When a river plunges vertically over a rock face, the result is a waterfall.

Question 20

Interlocking spurs

Answer 20

As the river meanders around obstacles, erosion is concentrated on the outside of the bends. At the same time, vertical erosion is taking place. The result is ridges of high land which project toward the river decreasing in height toward the river. These ridges alternate on either side of the river and are called interlocking spurs

Question 21

Deltas

Answer 21

Deltas are wetlands that form as rivers empty their water and sediment into another body of water,ee

Question 22

Levees

Answer 22

a natural or artificial wall that blocks water from flooding land

Question 23

waves

Answer 23

Most waves are formed by wind blowing across the surface of the sea or other large body of water. The friction between the wind and the surface of the water causes the water to move in a circular motion. Although the wave moves forward, the water does not move with it. Each particle of water simply moves around in a circular motion. As the wave moves into shallow water, it breaks.