Assessing building damage

1. Assessing building damage 30 mins This session will look at how to quantify the impacts of different hazards upon housing and infrastructure Bam, Iran 2003

2. Sessionobjectives • The key learning objectives of this session are to form an • understanding of: • Phases of assessment • Differences in building damage

3. Sessionobjectives • The key learning objectives of this session are to form an • understanding of: • Phases of assessment • Differences in building damage

4. Phases of assessment See session ‘assessment, monitoring evaluation’ • Damage assessment varies over time and needs to be undertaken • in series of steps: • 1. Preliminary assessment • 2. Initial assessment • 3. Detailed technical assessment • Macro assessment of entire affected area • Monitoring • Evaluation

5. Preliminary assessment • Before rapid assessment, assessment of building safety, • occupancy, loss of life is often undertaken by: • Search And Rescue (SAR) teams: deployed immediately after a disaster • United Nations Disaster Assessment and Coordination (UNDAC) teams: mobilized rapidly to coordinate the search and rescue operations with the national authorities. It is important to contact these teams in order to gain from them information concerning the scope and results of their preliminary assessments.

6. Preliminary assessment B A E C D SAR teams use standard marking system for buildings: A – name of team, date, time of visit/work B – types of risks encountered (hazardous materials) W water Gas gas leakage Chem chemical products EXPL explosive materials F fuels or other inflammable materials electricity risk of collapse radioactivity C – number of dead D – number of people unaccounted for E – number of people saved

7. Initial assessment • In the first days of the response, the objective of initial assessment is: • to achieve an understanding of the scale of the damage • to estimate where the damage is more severe • to inform the development of technical assessment criteria and housing damage categories • to bring together all available assessment capacity • 5. to initiate assessment coordination It is essential to achieve a successful handover to the technical specialists undertaking more detailed assessment.

8. Detailed technical assessment • The objective is to identify the relative damage to housing and • infrastructure in order to inform: • levels of assistance • forms of assistance • scale of assistance • location of assistance • priorities of assistance • vulnerabilities

9. Macro assessment of entire affected area Handbook for Estimating the Socio-Economic and Environmental Effects of Disasters (UN Economic Commission for Latin America and the Caribbean (ECLAC) and the World Bank, 2003) Damaged must be assessed at a national level in order to inform: 1. strategic planning 2. appeals processes 3. understandings of impacts upon the national and regional economy and environment Governments may agree an approach to macro assessment: following the Indian Ocean tsunami of 26 December 2004, a Tsunami Recovery Impact Assessment and Monitoring System (TRIAMS) was discussed and endorsed by the Global Consortium for Tsunami-Affected Countries IFIs have their own approaches to damage and loss measurement: the World Bank has used the methodology for disaster damage and loss assessment developed by the United Nations Economic Commission for Latin America and the Caribbean (UN-ECLAC), common in that region since 1972

10. Housing damages categories The categories of damage presented below have been used following conflicts to describe damage to housing, supported by 1-page rapid village and rapid housing assessment forms. Similar categories may be agreed following conflicts and disasters. Different categories may be developed for different building types. Category 0 Category 1 Category 2 Category 3 Category 4 No damage Minor damage, assistance required Partial damage, can be repaired Severe damage, can be repaired Destroyed, cannot be repaired

11. Basic building assessment • The following primary information may be gathered during early assessment to inform decisions on priority, what type of assistance is required, and whether repair should be considered: • Use1.a residence 1.d commerce • 1.b office 1.e factory • 1.c school 1.f hospital • 2. Type 2.a stone, adobe 2.d reinforced concrete structure • 2.b masonry/wooden roof 2.e steel structure • 2.c masonry/concrete roof • 3. Damage 3.a category 0 – no damage 3.d category 3 – severe damage, can be repaired • 3.b category 1 – minor damage 3.e category 4 – destroyed • 3.c category 2 – partial damage, • can be repaired • 4. Plan 4.a square 4.c L-shaped • 4.b rectangular 4.d complex • 5. Soil5.a soft 5.c rock • 5.b hard 5.d sloping

12. Coordination • Coordination needs to be achieved between stakeholders in order to: • Maximize capacity for assessment • Ensure all geographic areas are covered • Ensure assessment is consistent and response equitable • 4. Reinforce the relations between the stakeholders • It is rarely possible or valuable to enforce coordination. Therefore, • proactive steps must be taken to identify how to make • coordination valuable for each stakeholder.

13. Sessionobjectives • The key learning objectives of this session are to form an • understanding of: • Phases of assessment • Differences in building damage

14. Damage levels • Damage levels can depend upon a number of factors: • 1. hazards • 2. intensity • 3. location • 4. vulnerabilities • 5. buildings • 6. zones

15. Different damage from different hazards Each different hazard has its own different patterns: • Earthquakes may have 3 different directions of • motion: • vertical motion • horizontal motion • vertical and horizontal motion simultaneously • Floods may be: • fast-onset • slow-onset

16. Different damage from different intensity • Disasters have different intensities, measured with scales, such as: • earthquakes: (the Richter scale, 1-10, is now almost obsolete) • ModifiedMercalli intensity scale, 1-12, quantifies effects on the Earth's surface, humans, objects of nature, and structures, eg • Intensity 11, ‘Very Disastrous’: few, if any masonry structures remain standing; bridges destroyed; rails bent greatly • tornadoes: Fujita scale or Fujita-Pearson scale, 0-5 (6 levels) is based on damage to structures and vegetation, eg: • Intensity 4, ‘Devastating Damage’: 333–418 km/h; well-constructed houses levelled; structures with weak foundations blown away some distance; cars thrown and large missiles generated.The Enhanced Fujita Scale, which has been introduced in the USA, adds new construction methods • hurricanes: Saffir-Simpson Hurricane Scale, 1-5, is used for most Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms, eg • Intensity 4: 210–249 km/h winds; 4.0–5.5 metres storm surge

17. Different damage from different locations • The physical location of the disaster determines the impact upon • settlement: • flooding on a low-lying costal settlement • earthquakes under a settlement on an alluvial plain • cyclones entering a bay on a coast

18. Different damage from vulnerability • The population will be affected differently depending on their • social and economic status. • The more vulnerable groups are: • populations living in high-risk locations • populations living in poor-quality buildings • These vulnerable groups are most likely to be or become: • displaced populations • marginal groups • low-income populations • urban populations • Higher-income groups may be at greater risk if they adopt • new building technologies that do not incorporate traditional • hazard resistant design.

19. Different damage from different buildings • Different types of buildings will be damaged differently by the same • disaster: • poorly-built apartments blocks may be more vulnerable to earthquakes than houses with traditional seismically resistant design • schools may be less damaged than housing if they are built to higher-standards by government contractors following enforced building codes • older building may be damaged differently from newer building due to different construction, materials and techniques

20. Different damage from different zones • Within a disaster affected area, there will be different levels of • damage which may be categorised into different zones, with an • epicentre where the damage is greatest: • the zones of damage will describe the vulnerability of the location and the vulnerability of the buildings • zones may be highly-localised, for example in a flood where one street is damaged while the next street is not, because it is on high-ground • zones of damage approximate to a hazard map, which may be used for future disaster risk reduction and preparedness

21. Zones of housing damage Diagram: Transitional settlement and reconstruction after natural disaster (United Nations, 2008) Housing located in different zones will be damaged differently. Example of zones of housing damage, and movements between zones, following an earthquake

22. Summary • The key learning objectives of this session are to form an • understanding of: • Phases of assessment • Differences in building damage

23. Discussion Discussion in pairs Identify one disaster and list the differences in building damage: 1. 2. 3. 4. 5. 6.