rivers 🏞️

Question 1

mouth

Answer 1

the point at where the river reaches the sea/lake

Question 2

confluence

Answer 2

the point at which a tributary flows into another river

Question 3

watershed

Answer 3

a ridge of high land that forms the boundary between 2 adjacent drainage basins

Question 4

drainage basin

Answer 4

the area drained by a river and its tributes

Question 5

source

Answer 5

the start of a river, it can be a hollow where water accumulates or a natural spring where water reaches the surface

Question 6

tributary

Answer 6

a small stream that flows into a larger one

Question 7

river

Answer 7

a large natural stream of flowing water that empties into another water body ( lake , sea other river )

Question 8

the drainage basin system

Answer 8

precipitation
interception
evaporation
surface storage
infiltration
surface run off -( evaporation )
soil moisture storage -( through flow , channel flow )
percolation
ground water storage -( ground water flow )

Question 9

transpiration

Answer 9

water stored on the plants / leaves turn into vapour and spreads into the atmosphere

Question 10

why does the amount of interception vary from place to place

Answer 10

some areas have more vegetation than others

Question 11

why does the amount of interception vary at different times of the year

Answer 11

trees shed their leaves in the winter if it rains / snows the water is able to get into the ground

Question 12

river processes

Answer 12

erode, transport , deposition

Question 13

erode

Answer 13

hydraulic action
attrition
corrosion
abrasion

Question 14

transport

Answer 14

saltation
solution
traction
suspension

Question 15

river long profile

Answer 15

shows a change in the height of the course of a river from its source to its mouth. al long profile is usually concave and the slope becomes more gentle towards the mouth of the river

Question 16

upper profile

Answer 16

profile is steep
reduces hight very quickly
a lot of potential energy because of the steep drop
dominated by vertical erosion
narrow and steep sided
has little water volume

Question 17

middle profile

Answer 17

the gradient of the profile has reduced
lateral erosion is more as more of the profile has reduced
lateral erosion is more important
the channel is wider and the valley sides are less steep

Question 18

lower profile

Answer 18

less erosion , more deposition
potential energy has been replaces by energy from a high water volume
the river carries a large amount of load

Question 19

waterfall

Answer 19

the softer rock retreats backwards upstream
the overlying then becomes unsupported and falls / brakes away
the fallen material gets swirled around in the plunge pool

Question 20

meanders

Answer 20

a bend in a river
as the river gets more load it becomes more difficult to move along a straight channel
where the water hits the bank it erodes material in the areas where the water is travelling slower, the water has less energy and so deposits the eroded material

Question 21

how are meanders formed

Answer 21

As the water flows around the bend it is pushed further out causing the water flowing on the outside of the bend to be faster.
This means that erosion takes place and the bank is undercut by the process of hydraulic action and abrasion. This forms a river cliff.
On the inside the flow is slower and therefore deposition occurs to form a slip off slope or point bar.

Question 22

Potholes

Answer 22

If the river bends is uneven, pebbles become trapped in holes
Swirling currents cause the pebbles to rotate and erode circular holes in the river bed
This is done through the process of corrosion whereby sediment is trapped in the pot hole
Score away the base and the sides of it making it deeper and wider

Question 23

Oxbow Lake

Answer 23

Before
Lateral erosion
Land being eroded on both sides
Deposition
Line of fast flow

After
Neck of land removed by erosion of the banks from two side sides often at the time of flood
Position use of the ends of the cut off lake
Stagnant water
Meander Island
Oxbow Lake
Rivercliff

Question 24

Flood plain

Answer 24

A floodplain is an area of flat land either side of the river, which is often marsh. When a river floods it carries the load from the river onto the land either side. The big material is deposited first next to the river as it heavier. This builds up the banks making them taller these are called levees. The fine muddy material called alluvium is carried further. As the water seeps into the ground or flows back into the river, the sediment is left behind leaving the land much more fertile during normal flow the river deposits material from its load on the river bed causing the river to be lower than the surrounding floodplain.

Question 25

Deltas

Answer 25

As the speed of flow slows down, the energy is reduced and therefore the river cannot carry it load, especially if the river is heavily laden with soil and there is an absence of major title flows or currents. When sediment especially clay comes into contact with the saltwater its clumps together and becomes heavier., as a result of the river deposit sediment. As the settlement build up growth of vegetation raises as above sea level and distributor start to form where the river splits into many channels around the deposited sediment. This process is repeated and therefore further accumulation occurs over time.

Question 26

River flooding

Answer 26

The water in the river is called the river discharge A flood is an overflow of a large amount of water beyond this normal limits, especially over what is normally dry land The more the water gets intercepted the less run-off and discharge there is

Question 27

Factors affecting river discharge

Answer 27

When plants absorb or intercepts rainfall, it decreases discharge Impermeable rock increases discharge Steep pill increase discharge flatlands decrease discharge Totally packed, so you won't have the ability to absorb rainfall thus increasing run-off Saturated soil would already be full of water which would increase discharge Channel rainfall away for treatment increases discharge Surfaces were infiltration as possible decreases discharge

Question 28

Bangladesh case study

Answer 28

Physical Three rivers meet in Bangladesh 70% of the country is less than one meter above sea level tropical cyclones from the Bay of Bengal bring heavy rain and storm waves. Snow melts in the Himalayas in summer bringing more water 10% of the land is covered in rivers, lakes and swamps south Asia has a monsoon climate and experiences a wet season between May and September bringing 2000 mm of rain increased sedimentation in the river channels from eroded soil causes river bends to rise reducing your capacity. Global warming is causing sea levels to rise.

Question 29

Bangladesh case study

Answer 29

Economic GDP per capita is about $380 so there's little money to spend on the river management

Question 30

Bangladesh case study

Answer 30

Social Population growth in cities like a Dhaka is increasing the size of urban areas population growth in Nepal and North India has led to rapid deforestation

Question 31

Hard engineering

Answer 31

Involves putting in place of physical barrier between the land and the river

Question 32

Soft engineering

Answer 32

Involves working with nature to protect places from flooding

Question 33

Increase capacity

Answer 33

Get a bigger river to hold more water depending the dam

Question 34

Increase velocity

Answer 34

Get the water through the river, faster cementing the dams

Question 35

Reducing discharge

Answer 35

Slow down the flow of water into the river

Question 36

River investigation

Answer 36

Precaution Consider velocity Nature of the rocks Do not drink the water Work in pairs

Question 37

Depth

Answer 37

The measurement of death should be completed at a regular intervals across the whole with. This ensures a full picture of the changes in depth across the whole channel it also allows a mean depth to be calculated to use in the calculation of river discharge. To take accurate depth measurements: Work out the distance Place a meter rule into the water Ensure the meter rulers placed sideways on with the flat side facing the bank With the distance from the bed to the surface of the water Repeat this across the river

Question 38

Width

Answer 38

The measurement of the width is taken where the water surface comes into contact with the river banks Take accurate measurement: Measure from the point with a dry bank meats the water on one side to the point where the dry bank meets the water on the opposite side Ensure the tape is held taught and does not touch the water

Question 39

Wetted perimeter

Answer 39

The part of a river that touches the water