Analytical-Empirical Model for the Assessment of Earthquake Casualties and Injuries in a Major City in Israel -The Case of Tiberias

Mitigating the results of potential earthquakes requires an estimation of the casualties that may incur, and accordingly an appropriate response model can be developed. Based on an extensive literature review of the consequences of earthquakes, the following parameters were identified as significant in estimating human casualties:
1. The earthquake hazard in the designated area, such as active faults, liquefactions, landslides and ground motion amplifications;
2. Building and structural vulnerabilities to seismic hazards, assessed by an empirical or analytical approach combining simulation of seismic events with the data bases of structures, geological data, seismic data;
3. Assessment of the socio-economic conditions in the designated area, in order to estimate the potential population that was present in different building types at the time of the shake-out.
Israel is situated in an area prone to earthquakes. To present, the estimation of casualties that might be incurred during an earthquake in the region has not taken into consideration the different types of buildings and the presence of the population in the different structures at different time-frames. The research employs the semi-empirical approach to estimate the surviving casualties and
fatalities that might be caused by a potential earthquake. The city of Tiberius and its surroundings are used as the case-study to develop the model that will then serve as the basis for estimating the overall number of casualties that might be caused in the country.
The goal of the research is to develop and implement a semi-empirical model for casualty estimation that will enable to forecast the extent, types and severities of casualties that will result in Tiberius and its surroundings following several scenario of given earthquakes. This will enable the research group to assess the risk envelope caused by potential earthquake scenarios and develop strategies for preparedness of the structures and the population for the
given scenarios.
The following milestones have been achieved in this research:
1. Literature review – A comprehensive literature review of epidemiological, social, geological and structural aspects of seismic hazards (Chapter 2);
2. Classification of types of buildings – A detailed field survey was carried out in six census tracts and focused on data collection and engineering documentation of the building inventory. Based on the preliminary findings and the fact that the Israel Standard (413) for seismic design of structures was implemented only in some buildings constructed between 1985 and 1995 and in all of the buildings constructed since 1995, it appears that most of the building in these tracts
are residential and that about 3/4 (73%) have no or low earthquake resistance (Chapter 6);
3. Mapping present population in different time-frames - A detailed map of the population in the city of Tiberias (demographic and socioeconomic characteristics) and its occupancy in different structures across the city according to the time frames that have been detailed above was constructed (Chapter 3);
4. Adaptation of semi-empirical model to the Israeli structure and characteristics- A semi-empirical approach that combines casualty matrices of similar structures in Turkey along a Delphi-study of experts in Israel was introduced and implemented (Chapter 6);
5. Modified Delphi process to achieve consensus – This milestone has been fully
accomplished through a 2-iteration Delphi study with participation of 20 seismic hazards experts. The results of this study reinforce the high vulnerability of the study area (city of Tiberias) to seismic hazards. The exposed population characteristics that are documented in the literature as increasing the risk for earthquake-related injury and death.
6. Estimating damage to buildings – A detailed risk assessment that includes building damage assessment was developed: it is composed of four basic modules of a risk assessment model: hazard classification, building inventory, vulnerability, and loss assessment.
7. Estimating casualties and injuries that will be caused – Detailed assessment of the injury and mortality was accomplished using the Casualty matrices that were the outcome of the modified Delphi-study. It was observed that the Tiberias city area is highly vulnerable area for the given seismic events.
8. Validating the results of the model with reference to former earthquakes – Results of the present research were compared with seismic events such as the north Anatolian Fault event in Izmit 1999.
This research offers a multidisciplinary approach to a problem that has previously been studied mostly intra-disciplinarily. As earthquakes cause injuries through many mechanisms, a clear understanding of these pathways can facilitate emergency response planning and mitigation strategies. A comprehensive Analytical-Empirical model is developed that integrates an interdisciplinary research team that combines: geological, structural, emergency
medicine, and risk assessment approaches together to establish a unique comprehensive and robust methodology that is based in the well validated. The research outcomes will provide decision makers and public policy makers with risk-based tool for rationale policy making and resource allocation decision support tool.