River Landscapes and Processes- Flooding

Question 1

Flash floods

Answer 1

Floods that happen without warning

Question 2

5 physical causes of flooding

Answer 2

Prolonged rainfall, heavy rainfall, snow melting, rocks, relief

Question 3

Prolonged rainfall causing flooding?

Answer 3

Long period of rain, soil saturated, more runoff, increases discharge quickly

Question 4

Relief causing flooding?

Answer 4

Steep valleys, water reaches the channel quickly, increases discharge quickly

Question 5

Heavy rainfall causing flooding?

Answer 5

Increase in surface runoff, increase discharge

Question 6

Snowmelt causing flooding?

Answer 6

Lots of snow melt, lots of water in river quickly, increases discharge quickly

Question 7

Rocks causing river floods?

Answer 7

Impermeable rocks, no percolation, more runoff, increases discharge

Question 8

5 Human causes of flooding

Answer 8

Urbanisation, agriculture, industry, deforestation, drainage systems

Question 9

Urbanisation causing flooding?

Answer 9

Change in land use, impermeable materials, no infiltration, more runoff, increase discharge quickly

Question 10

Agriculture causing flooding?

Answer 10

More farming, less vegetation, less interception, more runoff, increases discharge quickly

Question 11

Industry causing flooding?

Answer 11

Factories at river mouth
Impermeable surfaces, more run off, risk of flooding
Deepen river for boats, increase capacity, less floods

Question 12

Deforestation causing flooding?

Answer 12

Trees removed for industry, urbanisation etc, less interception, increases discharge quickly

Question 13

Drainage systems causing flooding?

Answer 13

Water flowing straight to river, increased discharge, more risk of floods

Question 14

2 Social effects of flooding

Answer 14

Loss of life due to drowning
Damage to houses and belongings

Question 15

2 Environmental effects of flooding

Answer 15

Shortage of food from flooded farmland
Contamination of fresh water supplies
Destruction of habitats

Question 16

2 Economical effects of flooding

Answer 16

Communication links can be destroyed
Disruption to gas and electricity supplies

Question 17

4 Types of hard engineering for rivers

Answer 17

Dams, levees, channelisation, flood relief channels

Question 18

Dams/reservoirs
Def, ad, dis

Answer 18

Barriers to hold back water in artificial lakes
Ad- long lasting, produce hydro-electric power
Dis- expensive, can ruin the environment

Question 19

Embankments/levees
Def, ad, dis

Answer 19

High banks built on or near riverbanks
Ad- stops water spreading, can be natural, blend in
Dis- water could go over and be trapped, can burst

Question 20

Channelisation
Def, ad, dis

Answer 20

Deepening or straightening a river
Ad- water flows away quicker from places at risk
Dis- can put other places at risk, looks unnatural

Question 21

Flood relief channels
Def, ad, dis

Answer 21

Extra channels built leading from rivers
Ad- accommodates high flows, prevents overflow of banks
Dis- can be unsightly, expensive

Question 22

3 Types of soft engineering for rivers

Answer 22

Floodplain zoning, wash lands, river restoration

Question 23

Floodplain zoning
Def, ad, dis

Answer 23

Governments use areas differently based on flood risk
Ad- prevents new housing floods, leisure spaces in high risk areas
Dis- floodplains good for building,no demand for leisure spaces

Question 24

Wash lands
Def, ad, dis

Answer 24

Areas on the flood plain being allowed to flood
Ad- safe place for water to go, improves natural river processes
Dis- limit use of land, change in land use

Question 25

River restoration Def, ad, dis

Answer 25

Restoring a river to it's original course Ad- can slow down river through meanders, create natural habitats Dis- flood banks can still be needed, require change in land

Question 26

Hydrograph? Flood hydrograph?

Answer 26

A record of river discharge over a period of time Shows the change in discharge caused by a period of rainfall

Question 27

River discharge calculation

Answer 27

Cross sectional area x river's mean velocity

Question 28

Rising limb? Peak flow? Recession limb? Lag time?

Answer 28

Increase of flood water in a river Highest amount of discharge in a river Decrease of flood water in a river Difference between peak rainfall and peak discharge

Question 29

5 factors affecting storm hydrographs

Answer 29

Area, soil, rain intensity, urbanisation, afforestation

Question 30

How does area affect storm hydrographs?

Answer 30

Large basins receive more precipitation, more runoff, increases lag time

Question 31

How does soil affect storm hydrographs?

Answer 31

Thick soil, more infiltration (sand), increases lag time

Question 32

How does rain intensity affect storm hydrographs?

Answer 32

Intense rainfall, more runoff, steep rising limb, decreases lag time

Question 33

How does urbanisation affect storm hydrographs?

Answer 33

More impermeable surfaces, steep rising limb, decreases lag time

Question 34

How does afforestation affect storm hydrographs?

Answer 34

More interception, shallow rising limb, increases lag time