Rivers

Question 1

Moving down the river…

Answer 1

Width increases
Depth increases
Discharge increases
Velocity increases
Gradient decreases

Question 2

Infiltration

Answer 2

Movement of water into the soil from the surface

Question 3

Percolation

Answer 3

Movement of water into underlying rocks

Question 4

Saturation

Answer 4

When soil is full of water

Question 5

Surface run-off

Answer 5

When rainfall flows quickly over the surface of the ground until it reaches lakes and rivers

Question 6

Throughflow

Answer 6

Water flows slowly through the soil until it reaches the river

Question 7

Interception

Answer 7

When rainfall lands on the leaves and braches of trees and plants

Question 8

Groundwater flow

Answer 8

Water moves slowly through underlying rocks until it reaches a river

Question 9

Precipitation

Answer 9

Rain, hail, sleet or snow

Question 10

Physical reasons regarding flooding

Answer 10

Intense rainfall- water falls directly into the river
- rain infiltrates into soil and becomes saturated
- surface run of carried water directly to the river
Snow melt - winter snow melts very quickly on hills/ mountains an flows very quickly onto rivers
Impermeable rocks- do not allow water to infiltrate through surface runoff carries water quickly to river
Steep valley slopes - water runs quickly off valley slopes, surface runoff carries water directly to river

Question 11

Human reasons regarding flooding

Answer 11

Deforestation- prevents interception occurring, water infiltrates into soil until it becomes saturated, surface run off carries water directly to river
Urbanisation- concrete surface impermeable, prevents water from infiltrating into soil, surface runoff carries water directly to river

Question 12

The effects of flooding- Colorado USA (9th Sept 2013)

Answer 12

People- death toll of 10
-1,500 homes destroyed
-2,400 rescued by military helicopters
Environment - 400 miles of road destroyed
- dam broken
- 10 oil spills, water made toxic

Question 13

The effects of flooding- Pakistan (6th August 2010)

Answer 13

People- in Sindh province, 1.5 millin evacuated
- death toll of 1,600
Environment - 1.4m acres of cropland flooded
- cotton crop swept away
- 10,000 cows perished

Question 14

Hard engineering strategies -dams

Answer 14

Concrete structures used to control water discharge, can also be used to generate HEP
Expensive, erosion downstream
Can be used for recreational purposes

Question 15

Hard engineering strategies- channelization

Answer 15

River widened and deepened so that it can carry more discharge, can be straightened from a meander
Eye sore, not very natural, changing the river channel may lead to flooding downstream
Long lasting, provides protection for immediate area

Question 16

Hard engineering strategies- flood relief channels

Answer 16

Diverts flood water away from homes can be used for water sports eg kayaking
Expensive, requires lots of land
Safer as water is directed away from homes

Question 17

Hard engineering strategies- embankments/levees

Answer 17

Risen banks along the river so it can hold more discharge
Possibility of flooding still
Likelihood of flooding reduced

Question 18

Soft engineering strategies- afforestation

Answer 18

Trees planted in areas of intense rainfall, trees intercept rainfall, prevents saturation
Sustainable, good for environment
Slow process, fire risk

Question 19

Soft engineering strategies- washlands

Answer 19

Areas either side of the river channel which cannot be built upon, permeable so water can infiltrate
Turns into a habitats for birds, cheap as nothing is built upon

Question 20

Soft engineering strategies- flood zoning

Answer 20

Maps out areas most at risk of flooding, these areas cannot be built upon
Prevents future destruction
Cannot be used for land which has already been built upon or in developed countries

Question 21

Soft engineering strategies - flood warning systems

Answer 21

Series of sirens which give people early warning about the possibility of flooding
Cheap, effective way to prepare people
Could be vandalised, need to be tested annually, people may not have enough time to prepare (eg in flashfloods)

Question 22

Managing flooding- River Greta

Answer 22

2.2m high, 100m long floodwall, made of stone and partial glass, increases the discharge of water that can be carried
3 gates built along flood walls in Fitz Park next to Crosthwaite Road, can be closed if the discharge starts to rise and creates a barrier to prevent the land from flooding
EA monitor water discharge in River Greta everyday, if too high residents can be alerted via TV, mobile phone etc so they have enough time to prepare

Question 23

GIS MAP

Answer 23

Used to represent data, base map with layers of information on to represent flood risk etc