Topic 1 - Rivers

Question 1

Precipitation

Answer 1

Input

Water falls from clouds (as drizzle, rain, sleet and snow) towards the surface

Question 2

Interception

Answer 2

Store
The precipitation is caught and held for a short time by vegetation before it reaches the soil store. When there is more vegetation, more interception will occur and there is the potential for more evaporation, especially in the summer.

Question 3

Stem Flow & Through Fall

Answer 3

Transfers
The movement of water from the interception store to the surface sore, either by flowing down the stem/beaches (stem flow) or dripping off the leaves (through fall)

Question 4

Surface Storage

Answer 4

Store

Water is stored temporarily on the surface e.g. In puddles

Question 5

Infiltration

Answer 5

Transfer

Water enters the soil from the surface store.

Question 6

Overland flow / Surface runoff

Answer 6

Transfers
Water runs over the surface of the land following a rainstorm. This occurs when the soil either becomes saturated or because the rain intensity is too high and exceeds the infiltration capacity. It also occurs on impermeable surfaces.

Question 7

Soil storage

Answer 7

Store
Water that has infiltrated is stored in the surface layers of the soil before experiencing either throughflow or percolation.

Question 8

Throughflow

Answer 8

Transfer

Water moves downhill through the soil, close to and parallel with the surface, to the river

Question 9

Percolation

Answer 9

Transfer

Water moves further down into the soil from the soil store to the groundwater store

Question 10

Groundwater storage

Answer 10

Store

The permanent store of water in the lower layers of the soil and bedrock

Question 11

Groundwater flow

Answer 11

Transfer

The movement of water from the groundwater store in the lower layers of the soil and the bedrock to the river.

Question 12

Evaporation

Answer 12

Output
Water is changed into water vapour from various stores such as interception and surface storage. The main factor affecting the rate of evaporation is temperature

Question 13

Transpiration

Answer 13

Output
Water vapour is taken from vegetation and plans into the atmosphere. This is affect by factors such as the vegetation type (e.g. deciduous trees lose their leaves in winter to reduce transpiration) and moisture availability.

Question 14

What factors affect transfers and stores of matter in a drainage basin?

Answer 14

Vegetation 
Soil type
Seasons
Geology
Urban Areas
Relief
How heavy the rain is

Question 15

Abrasion

Answer 15

The most effective form of river erosion and occurs when the river uses its load to erode the bed and banks by scraping and scouring. It is particularly effective at times of higher discharge when the river has enough energy to transport larger particles.

Question 16

Hydraulic Action

Answer 16

Occurs due to the physical force of the water against the bed and banks. On the outside bends to meanders, for instance, the currents push water into cracks, causing pressure that leads to erosion.

Question 17

Solution / Corrosion

Answer 17

The dissolving of soluble materials in the bed and banks by weak acids in river water. A chemical reaction rather than a physical process and so is not dependent on the energy levels in the river. Most effective in rocks containing carbonates, such as limestone.

Question 18

Attrition

Answer 18

Occurs when the load particles come into contact with other load particles and the bed and banks. As a result the rough edges are smoothed and the particles become smaller and more rounded.

Question 19

Suspension

Answer 19

The smaller particles of clay, silt and sand can be carried along by the turbulence of the river.

Question 20

Solution

Answer 20

The material eroded by corrosion is carried along and dissolved in the water m. This form of transportation can be significant in limestone areas, but tends to be less important in other areas

Question 21

Saltation

Answer 21

The smaller bedload, such as pebbles and gravel, can be bounced along the riverbed by turbulence during times of higher discharge

Question 22

Traction

Answer 22

The largest boulders in the river can be rolled along the riverbed during times of very high discharge