A Next-Generation Open-Source Tool for Earthquake Loss Estimation

Abstract

Earthquake loss estimation (ELE), generally also referred to as earthquake risk assessment, is a comparably young research discipline which, at first, relied on empirical observations based on a macroseismic intensity scale. Later, with the advent of methodologies and procedures that are based on theoretical simulation in estimating physical damage under earthquake loading, the analytical approach for ELE was formulated. The open-source software SELENA, which is a joint development of NORSAR (Norway) and the University of Alicante (Spain), is undergoing a constant development. One of the more recent features being included is the possibility to address topographic amplification of seismic ground motion. Additionally, SELENA has been adapted by including various methods for the analytical computation of structural damage and loss. SELENA now offers complete flexibility in the use of different types of fragility curves based on various ground motion intensity parameters (e.g. PGA, Sa, Sd), which has been suggested by many recently released guidelines (e.g. FEMA P-58, GEM-ASV, SYNER-G, HAZUS- MH). Besides, under the framework of the ongoing Horizon 2020 LIQUEFACT project, SELENA is extended in order to allow the consideration of liquefaction-induced ground displacements and respective structural damage. In general, software tools for ELE are particularly useful in two different settings, i.e., for disaster management and (re)insurance purposes. Both sectors pose very different demands on ELE studies: while the (re)insurance sector is foremost interested in the direct and indirect economic losses caused by an earthquake to its insured physical assets, those institutions (often governmental and non- governmental organizations) in charge of disaster emergency management and response are more interested in reliable estimates on human losses and the potential short- and long-term social consequences. Being aware about these peculiar differences between software tools for disaster management and insurance applications, NORSAR/UA thereby offers two in its core similar software tools, i.e., the open-source software SELENA and the proprietary software PML (Probable Maximum Loss) which is actively used by the insurance association in Chile (South America) since 2011.