lec 2 ~ natural hazards + disasters

what is a hazard?

a phenomenon that could become a problem/disaster

what is a disaster?

an event involving significant number of people and/or economic damage

why has the number of disasters increased over the years?

inc of hydrometeorological hazards due to climate change

disasters were more under recorded in the past

why has the overall number of people affected increased over the years?

population has grown as well

why have the number of deaths from disasters decreased over the years?

better tech

more awareness/education

better preventative measures (eg. better infrastructure)

what is an official disaster based on OFDA/CRED?

10+ deaths and/or

100+ people affected and/or

declaration of state of emergency

what is an official disaster based on UN?

serious disruption of a community

widespread human, material, economic or enviro impact

exceeds communities ability to cope on own

what is exposure?

the likelihood of a certain hazard occurring

what is sensitivity?

the degree to which a community/individual could be impacted and level of their preparedness

what is vulnerability?

vulnerability = exposure + sensitivity

what is probability?

the statistical likelihood of an event occurring

what is a recurrence interval (return period)?

the average number of years between an event of a certain size in a location

are natural hazards interconnected?

yes

are small, frequent events common or uncommon?

common

are big, unfrequent events common or uncommon?

uncommon

how does the news affect our perception of disasters?

“spectacular” disasters get more coverage despite not being as common or as devastating

what are rapid-onset disasters?

begin quickly

people dont have time to prepare

most are short duration

eg. earthquakes

what are slow-onset disasters?

take days or weeks to develop

people have tiem to prepare

most are long duration

eg. floods

what are very slow-onset disasters?

take months, years or decades to develop

eg. sea level rise, drought, climate change

why do people live where they are vulnerable to hazards?

can provide fertile soils and scenic views

memory of previous disasters is gone

community established before hazard was known

no option

what is mitigation?

taking actions to physically reduce exposure of community to hazard

what is adaptation?

accepting the hazard will occur and taking actions to reduce the impact, sensitivity and vulnerability of the community

what are the approcahes to mitigation?

1\. affecting the cause - reducing likelihood of it occurring

2\. modifying the hazard - constructing engineering solutions or relocation

3\. modify potential loss - reduce economic and social sensitivity and vulnerability (eg. earthquake resistant buildings)

4\. spread the loss - distribute economic loss to broader group

5\. plan for loss - measure budget of damage that hazard could cause

6\. bear the loss

what are the approaches to natural hazard assessments?

1\. assessment of degree of exposure

2\. evaluation of communities sensitivity to a hazard