Flooding

Question 1

definition of hazard

Answer 1

a dangerous phenomenon, substance, human activity or condition that MAY cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage

Question 2

definition of disaster

Answer 2

a dangerous phenomenon, substance, human activity or condition that HAS cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage

Question 3

definition of hazard management

Answer 3

what humans do, or should do, to minimise the effects of hazards

Question 4

definition of aggravating factors

Answer 4

range of challenges that can exacerbate the effects of hazards, resulting in increased frequency, complexity and severity of disasters

Question 5

what is hazard severity?

Answer 5

how severe a hazard is based on controls of: duration, frequency, magnitude etc. and can change over time

Question 6

definition of risk

Answer 6

the potential loss of life, injury or destroyed or damaged assets which could occur to a system, society or a community in a specific period of time, determined probabilistically as a function of hazard, exposure, vulnerability and capability

Question 7

definition of vulnerability

Answer 7

the characteristics of a person or group and their situation that influence their capacity to anticipate, cope with, resist and recover from the impact of a natural hazard

Question 8

definition of resilience

Answer 8

a process linking a set of adaptive capacities to a positive trajectory of functioning and adaptation after a disturbance

Question 9

what factors impact post-disaster recovery?

Answer 9

resources, community size, connectedness vs isolation, duration and intensity, actions and timings of external agencies, attitude and political initiatives influencing confidence

Question 10

definition of flooding

Answer 10

temporary inundation of normally dry land by water from rivers bursting, surface runoff or tidal or coastal waters

Question 11

what is pluvial flooding? (flash floods and surface water)

Answer 11

rapid-onset, short duration flooding caused by intense rainfall and in catchment conditions

Question 12

what is fluvial flooding? (river floods)

Answer 12

occurs due to rivers busting their banks, from widespread/long duration precipitation and melting snow. days to weeks to occur

Question 13

what is coastal flooding (storm surge)?

Answer 13

impacts low-lying coastal areas, caused by: tides, storm surges, tropical cyclones, high winds and tsunamis

Question 14

what are flood impacts?

Answer 14

floods can carry mud and debris, sewage, and pollutant. can be destructive to land and built environment. health risks of disease and psychologically

Question 15

risk equation

Answer 15

likelihood of a hazard occurring x consequences of that hazard occurrence

Question 16

what is risk avoidance?

Answer 16

avoid the problem and the rewards that may come with it

Question 17

what is risk reduction?

Answer 17

methods to reduce the likelihood and/or severity of loss

Question 18

what is risk retention?

Answer 18

accepting loss when it occurs

Question 19

what is risk transfer?

Answer 19

causing another party to accept the risk e.g. insurance

Question 20

what is low-land (slow) river flooding?

Answer 20

inundation of low-lying land from burst river banks, caused by excessive long-duration precipitation/snowmelt

Question 21

what is a floodplain?

Answer 21

areas of frequent natural flooding connected to a river network

Question 22

what is flash (rapid-onset) flooding?

Answer 22

rapid, sudden low-lying flooding caused by intense rainfall or breaking dam.

Question 23

how to estimate extreme event occurrences?

Answer 23

through annual probabilities

Question 24

define return period

Answer 24

the average frequency of occurrence of an event of a particular magnitude e.g. 1 in 100 year event

Question 25

define annual exceedance probability

Answer 25

the probability that a flood will exceed a give level in any year

Question 26

benefits of flood mapping

Answer 26

determines impact area both during and post-event, generate flood hazard zone maps and source of data to understand flood models

Question 27

ways of gathering flood mapping data

Answer 27

remote sensing - LIDAR, drones, social media/crowdsourcing, aerial imagery, satellite imagery, and SAR (synthetic aperture radar)

Question 27

what are the principles of flood modelling?

Answer 27

1. based off past flood events
2. model validation from this data
3. used for prediction of unseen events

Question 28

what is the purpose of risk management?

Answer 28

reduce the likelihood of the hazard occurring and the consequences of the hazard

Question 29

what are the flood management aims?

Answer 29

sustainable development, maximising net benefits from floodplains, minimising loss of life and environmental preservation

Question 30

what are ways to naturally manage catchment-based floods?

Answer 30

1. increasing roughness
2. attenuating flows
3. infiltrating flows (tree planting)

Question 31

definition of flood mitigation

Answer 31

human intervention in river catchments which is intended to reduce flood risk through reducing flood likelihoods and impacts

Question 32

what are flood mitigation structural measures?

Answer 32

protect against flooding through hard engineering, through dams, walls, channnelisation, channel diversions and pumping stations

Question 33

what are flood mitigation non-structural measures?

Answer 33

management measures such as zonation, planning, proofing homes and localised levees/not involving physical construction