Drainage Basin Systems

Question 1

What is Condensation?

Answer 1

The process of water vapour changing to liquid water

Question 2

What are Cryospheric Processes?

Answer 2

Processes that affect the total mass of ice at any scale.

They include accumulation and ablation.

Question 3

What is accumulation?

Answer 3

The build up of ice mass

Question 4

What is Ablation?

Answer 4

The loss of ice mass

Question 5

Define a Drainage Basin

Answer 5

A drainage basin is an area of land drained by a river and its tributaries, including water found on the surface, soil and near-surface geology.

Question 6

What is evaporation?

Answer 6

Evaporation is where liquid water changes a gas. This requires energy, provided by the sun and aided by the wind.

Question 7

What is Evapotranspiration?

Answer 7

The total output of water from the drainage basin directly back into the atmosphere.

Question 8

What is Groundwater flow?

Answer 8

The horizontal flow of water once it has reached the water table.

Question 9

What is infiltration?

Answer 9

The downward movement of water from the surface into the soil

Question 10

What is interception storage?

Answer 10

The precipitation that falls on the vegetation or human cover is temporarily stored on these surface.

Question 11

What happens to water stored in interception storage?

Answer 11

Intercepted water is either evaporated to the atmosphere or absorbed by canopy surfaces and transferred to the ground surface

Question 12

What is overland flow?

Answer 12

The tendency of water to flow horizontally across land surfaces when rainfall has exceeded the infiltration capacity of the soul and all surface stores are full to overflowing

Question 13

What is Percolation?

Answer 13

The downward movement of water within the rock under the soil surface. Rates vary depending on the nature of the rock.

Question 14

What is Run-off?

Answer 14

All the water that enters a river channel and eventually flows out of the drainage basin

Question 15

What does saturated mean?

Answer 15

This applies to any water store that has reached its maximum capacity

Question 16

Define Stemflow

Answer 16

Stemflow is the portion of precipitation intercepted by the canopy that reaches the ground by flowing down stems, stalks or tree bole

Question 17

What is a storm/rainfall event?

Answer 17

An individual storm is defined as a rainfall period separated by dry intervals of at least 24 hours and an individual rainfall event is defined as a rainfall period separated by dry intervals of at least 4 hours.

Question 18

What is Throughfall?

Answer 18

The portion of the precipitation that reaches the ground directly through gaps in the vegetation canopy and drips from leaves, twigs and stems.

Question 19

What is ThroughFLOW?

Answer 19

The horizontal flow of water through soil or rock layers.

Movement of water down-slope through the subsoil under the influence of gravity. Particularly effective when underlying permeable rock prevents downward movement.

Question 20

Define Transpiration

Answer 20

The loss of water from vegetation through pores (stomata) on their surface.

Question 21

What is the Water Balance?

Answer 21

The balance between inputs and outputs in a drainage basin

Question 22

When does Transpiration occur?

Answer 22

It occurs mostly when the canopy surface rainwater storage exceeds its storage capacity.