rivers

Question 1

what is evapotranspiration?

Answer 1

-veg intercepts and takes up water through roots

Question 2

overland flow?

Answer 2

-upland streams flow down-hill and join at confluences
to form slow-moving wide rivers

Question 3

drainage basin?

Answer 3

-drains all water which lands on earths surface

Question 4

features of a drainage basin?

Answer 4

-watershed
-source
-confluence
-tributary
-mouth

Question 5

drainage density?

Answer 5

-number of tributaries in draininage basin

Question 6

what is traction?

Answer 6

-large rocks roll along river bed

Question 7

what is saltation?

Answer 7

-smaller materials bounce along the river bed

Question 8

what is suspension?

Answer 8

-lighter materials are carried within river flow

Question 9

what is solution?

Answer 9

-materials are dissolved in water

Question 10

what is the wetted perimeter?

Answer 10

-length of wet part of channel cross-section

Question 11

cross-section area?

Answer 11

-area of flowing water

Question 12

what is river discharge?

Answer 12

-the amount of water flowing in a channel

Question 13

what is hydrualic action?

Answer 13

-air is forced into headland cracks, removing material

Question 14

what is abrasion?

Answer 14

-material in water rubs against banks

Question 15

what is attrition?

Answer 15

-material carried by river hit each other and become smaller and rounder

Question 16

what is corrosion?

Answer 16

-rocks dissolve by acidic water

Question 17

what is the long profile of a river?

Answer 17

-shows the changes in river gradient from source to mouth

Question 18

what is the cross profile?

Answer 18

-sections from 1 bank to another

Question 19

formation of a waterfall…

Answer 19

-soft rock erodes quicker, undercutting the hard rock and creating a plunge pool
-this leads to the development of an overhand of hard rock which overtime collapses
-overhand falls into the plunge pool, increasing abrasion and making plunge pool deeper
-process repeats and waterfall retreats upstream.

Question 20

formation of a v-shaped valley…

Answer 20

-vertical erosion is dominant in the upper course of a river
-this cuts down into the river bed and deepens the river channel
-weathering and mass movement leads to material from valley sides collapsing into river
-forming a v shaped valley

Question 21

formation of a meander…

Answer 21

-fastest flow on the outside of river bend (leads to erosion)
-erosion undercuts riverbank
-riverbank collapses and the edge of the meander moves further out
-slowest flow on inside of river bend, leads to deposition forming slip-of slope
-erosion on one side and deposition on the other leads to meandering migrating across the valley.

Question 22

formation of an oxbow lake…

Answer 22

-as erosion continues, the neck of the meander is worn away and gets narrower and narrower
-during flooding, the river cuts straight across the neck
-loop of meander gets sealed off and turns into an oxbow lake
-lake gets covered with weeds in time

Question 23

what is vertical erosion?

Answer 23

-dominant in upper course of river
-inc depth of river and valley

Question 24

what is lateral erosion?

Answer 24

-dominant in the middle and lower course
-inc width of river as it erodes sideways

Question 25

why is lateral erosion more effective than vertical erosion in lower reaches of river?

Answer 25

-vertical erosion makes channel deeper but lateral widens river, better so more deposition can flow into mouth

Question 26

how are leeves formed?

Answer 26

-as water spills out from flood the heaviest particles are deposited 1st
-every time a flood occurs more particles are added to these deposits
-build-up and form levees

Question 27

what is a flood plain?

Answer 27

-flat area of land found on either side of river in lower course

Question 28

whats an estuary?

Answer 28

-meeting point between river and sea

Question 29

whats a delta?

Answer 29

-depositional feature made from material dropped by river
-formed when river lacks energy

Question 30

oppotunities from rivers…

Answer 30

-leisure
-tourism
-source of water
-fishing
-transportation
-generating electricity

Question 31

causes of flooding…

Answer 31

-heavy rainfall
-landslides
-ice melt

Question 32

damage caused by flooding…

Answer 32

-death
-water disease spread
-transport routes damaged
-loss of farm land

Question 33

factors which can inc flood risk?

Answer 33

-deforestation
-urbanisation
-agriculture
-climate change

Question 34

factors affecting flood RISK

Answer 34

-relief
-rock type
-soil
-weather

Question 35

protection from floods…

Answer 35

-dams/reservoirs
-flood relief channels
-straightened channels
-flood plain zoning
-afforestation