Operational Earthquake Loss Forecasting in Italy: Preliminary Results

1. Operational Earthquake Loss Forecastingin Italy: Preliminary Results I. Iervolino,1 E. Chioccarelli,1 M. Giorgio,2W. Marzocchi,3 A. Lombardi,3 G. Zuccaro,1 F. Cacace.1 1Università degli studi di Napoli Federico II, Naples, Italy. 2Seconda UniversitàdegliStudi di Napoli, Aversa (CE), Italy. 3Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy. Second European Conference on Earthquake Engineering and Seismology – Istanbul (Turkey), August 25th 2014.

2. Introduction 1/10 • The CASSANDRA system of INGVprovides weekly rates of events with magnitude (M) 4+ for a 0.1° grid including the whole country. (Updated daily.) • TheItalian Civil Protection asked to investigate whether it is possible (and useful) to use the INGVdata to produce consequence estimates to be used as a decision support system for seismic risk management. • The framework is that of performance-based earthquake engineering, that is including probabilistic measures of hazard, vulnerability and exposure at a National scale.

3. Passing from M 4+ rates to loss 2/10 1. Probabilistic seismic hazard analysis based on OEF Site of interest (w,z) Area of interest The goal here is to pass from OEF rates at a cell to rates of events causing some seismic intensity (MS) at a site of interest (for example one where exposure to seismic risk exists) R(x,y,w,z) Source cell (x,y) Rates of events at (w,z) with MS=msbecause of earthquakesoccurring at (x,y) Distribution of M for earthquakes at (x,y) MS predictionequation (attenuation law) OEF rates at (x,y) Indicating thatvaries with time (OEF updates) Indicatingdependenceon recorded history

4. Passing from M 4+ rates to loss 3/10 2. Weekly rates of events causing building damage Site of interest (w,z) Area of interest The goal here is to pass from OEF rates at a cell to rates of events causing some damage state (DS) in a buildingof certain structural typology (k) at site of interest R(x,y,w,z) Source cell (x,y) Rates of events at (w,z) causing DS=dsbecause of earthquakesoccurring in the whole area Probability of some damage state to a structure of typology K givenmsintensity OEF rates at (x,y) Same as per the previous slide Summing up over all source cellsgives the totaldamage rate at (w,z) site

5. Passing from M 4+ rates to loss 4/10 3. Weekly rates of events causing individual loss Site of interest (w,z) Area of interest The goal here is to pass from OEF rates at a cell to rates of events causing some individual consequence to an occupant of a building of a given structural typology (k) at site of interest R(x,y,w,z) Source cell (x,y) Summation is to account thatcasualty can be caused by any DS Rates of events at (w,z) causingcasualty in buildings of typology k Probability of casualty in a building of typology K givendamage state DS=ds OEF rates at (x,y) Same as per the previous slide

6. Passing from M 4+ rates to loss 5/10 Expected losses in the week after the OEF rates release In the short-term, it may be assumed that the rates just shown are constant, that is the occurrence of events follows a point-wise Poisson stochastic process, the parameter of which is updated at each OEF release. Expectednumber of buildings of typology k at (w,z) in damage state DS=ds in the week after OEF rates release Buildings of typology k at (w,z) Rate of eventscausingdamage to typology k at (w,z) Expectednumber of displaced and shelter-seekingpeople One week Expectednumber of casualties due to damage to buildings of typology k at (w,z) in the week after OEF rates release Occupants in buildings of typology k at (w,z) Rate of eventscasualties in buildings of typology k at (w,z) Expectednumber of fatalities and injuries One week

7. Hazard, vulnerability, and exposure models for Italy Operational earthquake loss forecasting (OELF) procedure summary 6/10 Rate of events in the source cell of interest from OEF Intensityattenuation law Site (municipality) of interest (w,z) Probability of anymacroseismicintensitylevelgiven the event Seismicswarm area Probability of anydamagelevel for anyvulnerabilityclassgiven the event Vulnerability model Probabilityof casualties or injuries for anydamagelevel in anyvulnerabilityclassgiven the event Sum-up over allsource cells Source cell (x,y) Expectednumber of damagedbuildings Expectednumber of injures, fatalities, displacedpeople Exposure data for residents at the site of interest Inventory data for buildings at the site of interest

8. Hazard, vulnerability, and exposure models for Italy Vulnerabilitybased on damageprobabilitymatrices 7/10 Probabilities of casualty given structural damage Exposure by municipality Buildings per vulnerabilityclass Residents per vulnerabilityclass

9. MANTIS K. 8/10 MANTIS K. The system for continous OELF in Italy

10. MANTIS K. 9/10 Local OELF at 00:00 of August 24 2014 (around the cell with maximum OEF rate) • Area of interest • Expected weekly losses (Aug. 24-31)

11. 10/10 Summary and conclusions • The study discussedthe feasibility of probabilistic short-term seismic loss (risk) assessment in Italy, based on OEF. Risk metrics investigated are the expectednumber of fatalities, injuries, and displaced residents in one week. • Probabilistically-consistent short-term seismic risk assessment in Italy appears to be feasible, yet it is conditional to the OEF and vulnerability/exposure models available. • Risk measures seem to be sensitive to the short-term seismicity variations inferred by OEF, which provide the largest seismicity right after the mainshock. • A prototypal system for continuous OELF analysis, MANTIS K., is currently under experimentation. It automatically receives OEF data from the CASSANDRA system of INGV and performs OELF for the whole country as well as for the region around the location where the largest seismicity is observed.

12. Operational Earthquake Loss Forecastingin Italy: Preliminary Results I. Iervolino,1 E. Chioccarelli,1 M. Giorgio,2W. Marzocchi,3 A. Lombardi,3 G. Zuccaro,1 F. Cacace.1 1Università degli studi di Napoli Federico II, Naples, Italy. 2Seconda UniversitàdegliStudi di Napoli, Aversa (CE), Italy. 3Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy. Second European Conference on Earthquake Engineering and Seismology – Istanbul (Turkey), August 25th 2014.