Assessing building damage

1. Assessing building damage • 189 Algeria, 2003 This workshop will look at how to quantify the impacts of different hazards upon housing and infrastructure

2. Workshopobjectives ! • The key learning objectives of this workshop are to form an • understanding of and share experience on : • Presentation: phases of assessment • Workshop: differences in building damage

3. Handover from SAR teams B A E C D Search And Rescue teams use standard marking systems: A – name of team, date, time of visit/work B – types of risks encountered 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

4. Macro assessment of entire affected area Handbook for Estimating the Socio-Economic and Environmental Effects of Disasters (ECLAC and the World Bank, 2003) Damages must be assessed at a national level in order to inform: 1. strategic, programme and project 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

5. 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

6. Factors influencing levels of damage • The type and scale of damage to buildings depend upon a number • of factors: • 1. hazard: different damage from different hazard • 2. intensity: different damage from different intensity • 3. vulnerability: different damage from vulnerability • 4. buildings: different damage from different buildings • 5. zones: different damage from different zones

7. Workshop groups Key point Each group will be allocated one of the factors and will discuss how the damage levels change with: Group 1: differenthazards Group 2: differentintensities Group 3: differentvulnerabilities Group 4: differentbuildings Group 5: differentzones Discussion in groups Each group agrees a key point

8. Group 1 key point: different hazards Key point Question: How does the damage level change with different hazards? Group 1 shares one key point with the other groups

9. Different damage from different hazards Each different hazard has its own different patterns: • Conflicts: • low-intensity conflicts and civil disturbances • high-intensity conflicts • Earthquakes may have 3 different directions of • motion: • vertical motion • horizontal motion • vertical and horizontal motion simultaneously • Floods may be: • fast-onset • slow-onset

10. Group 2 key point: different intensity Key point Question: How does the damage level change with different intensity? Group 2 shares one key point with the other groups

11. Different damage from intensities • 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

12. Group3keypoint:differentvulnerabilities Key point Question: How does the damage level change with different vulnerability? Group 3 shares one key point with the other groups

13. Different damage from vulnerabilities • 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.

14. Group 4 key point: different buildings Key point Question: How does the damage level change for different buildings? Group 4 shares one key point with the other groups

15. Different damage for 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

16. Group 5 key point: different zones Key point Question: How does the damage level change with different zones? Group 5 shares one key point with the other groups

17. 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 Transitional settlement and reconstruction after natural disasters (United Nations, 2008)

18. Bibliography 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) Transitional settlement and reconstruction after natural disasters(United Nations, 2008)