Drainage Basin

Question 1

What is a drainage basin?

Answer 1

It is an area of land drained by a river and it’s tributaries

Question 2

What is a drainage basin also known as?

Answer 2

A catchment

Question 3

Is a drainage an open or closed system?

Answer 3

An open system

Question 4

Why is it in open system?

Answer 4

It has inputs of precipitation and outputs as it drains all the water that lands on earth into the sea of through evaporation

Question 5

What factors effect the character and development of a drainage basin?

Answer 5

Climate, vegetation, soil structure and land use

Question 6

Can drainage basins be big?

Answer 6

Yes, they can cover lots of square miles of land

Question 7

An example of a river with a big drainage basin?

Answer 7

The river Nile’s drainage basin that covers 12 countries with 73% of it being in Sudan and Egypt

Question 8

How many features of a drainage basin are there?

Answer 8

5

Question 9

What are the 5 features of a drainage basin?

Answer 9

Mouth
source
watershed
confluence
tributary

Question 10

Where/ what is the mouth

Answer 10

It is the end of the river where the river meets the sea or ocean

Question 11

Where is the confluence and what is it?

Answer 11

It is just before the mouth and it is where two or more streams or tributaries meet to make one single channel

Question 12

What is the source and where is it?

Answer 12

The source is normally at the top of the drainage basin and it is where the water enters as an input into the drainage basin this tends to be precipitation

Question 13

What is the water shed and where is it?

Answer 13

The watershed defines one drainage basin from another, it sounds out the boundaries for one singular drainage basin. It is found on a raised bit of land with water in it - it is practically useful for looking ta the follow of water in the drainage basin and for environmental scientists

Question 14

What is a tributary and where can you find it?

Answer 14

They can be found anywhere but often on the path from the main and primary water source to the confluence and high up on ground. They carry water and manage surface runoff

Question 15

What is the input in the drainage basin?

Answer 15

Precipitation

Question 16

What is the output in the drainage basin?

Answer 16

River discharge
evaporation
transpiration
evapotranspiration

Question 17

What are the stores in a drainage basin?

Answer 17

Groundwater storage
Surface storage
Vegetation storage
Soil moisture storage
Channel storage

Question 18

What is the only feature of a drainage basin that is considered half a store and half a transfer and why?

Answer 18

The atmosphere - because clouds store water but they also move it around the planet

Question 19

What are the flows/transfers of the drainage basin?

Answer 19

Groundwater/base water flow
Streamflow/leaf drip
surface runoff
throughflow
Infiltration
Percolation
Chanel flow

Question 20

What is the water table?

Answer 20

It is the top zone of saturation where all pore spaces in the rock if filled up of water - no more room in the rock to store water as it is all taken up

Question 21

What is the volume of water leaving the drainage basin measured in?

Answer 21

Cumecs

Question 22

What is the percent of interception buildings and plants can have and how does this effect the drainage basin?

Answer 22

40% - so there is a reduction in soil erosion and flooding

Question 23

What is the soil store called where water is retained in the pores?

Answer 23

interstices

Question 24

What is transpiration?

Answer 24

The changing of water to water vapour by plants naturally

Question 25

What is evaporation?

Answer 25

The changing of water to water vapour over any body of water caused by heat energy

Question 26

Can a drainage basin be either above or below ground?

Answer 26

Yes it can be both

Question 27

What are the 5 factors when a drainage basin is above ground and what do they mean?

Answer 27

Throughflow - precipitation that reaches the ground with ought being intercepted by any plants or vegetation Drip flow- the movement of water downwards from a plant leaf - some plants have adapted to increase this by having drip tips and waxy cuticles Trunk + Steam - Flow of water through either the trunk or stem Overland surface flow - water that flows over the surface and there are 2 types channel flow and sheet flow

Question 28

What are the two types of overland surface flow?

Answer 28

Channel - water flows from smaller channels <30cm width or depth and is a defined stream pattern sheet - a layer of water on the surface either excess surface runoff or increased precipitation and no infiltration - hortonian

Question 29

What is Hortonian overland flow?

Answer 29

tendency of water to flow horizontally across the land when rainfall exceeds infiltration and there is no water storage so the water runs on the surface as sheet flow