A Review of the Study on the Uncertainty of Earthquake Loss Estimation

In this paper,the types of research methods that contain uncertainty are first introduced,and then the description is concentrated on the progress of study on different types of uncertainties in seismic disaster and loss estimation. The main methods applied to uncertainty study are reviewed. Preliminary discussion of the problems currently existing in estimation is also made.

A Physics‑Based Seismic Risk Assessment of the Qujiang Fault:From Dynamic Rupture to Disaster Estimation

This study achieved the construction of earthquake disaster scenarios based on physics-based methods-from fault dynamic rupture to seismic wave propagation-and then population and economic loss estimations.The physics-based dynamic rupture and strong ground motion simulations can fully consider the three-dimensional complexity of physical parameters such as fault geometry,stress field,rock properties,and terrain.Quantitative analysis of multiple seismic disaster scenarios along the Qujiang Fault in western Yunnan Province in southwestern China based on different nucleation locations was achieved.The results indicate that the northwestern segment of the Qujiang Fault is expected to experience significantly higher levels of damage compared to the southeastern segment.Additionally,there are significant variations in human losses,even though the economic losses are similar across different scenarios.Dali Bai Autonomous Prefecture,Chuxiong Yi Autonomous Prefecture,Yuxi City,Honghe Hani and Yi Autonomous Prefecture,and Wenshan Zhuang and Miao Autonomous Prefecture were identified as at medium to high seismic risks,with Yuxi and Honghe being particularly vulnerable.Implementing targeted earthquake prevention measures in Yuxi and Honghe will significantly mitigate the potential risks posed by the Qujiang Fault.Notably,although the fault is within Yuxi,Honghe is likely to suffer the most severe damage.These findings emphasize the importance of considering rupture directivity and its influence on ground motion distribution when assessing seismic risk.

Rapid estimation of disaster losses for the M6.8 Luding earthquake on September 5,2022

An M6.8 earthquake occurred in Luding,Sichuan Province,China,on September 5,2022.Since towns and villages in the earthquake-stricken area are densely populated,the earthquake caused severe fatalities and economic losses.Rapid estimation of earthquake intensity and disaster losses is significantly important for post-earthquake emergency rescue,scientific anti-seismic deployment,and the reduction of casualties and economic losses.Therefore,we make a preliminary rapid estimation of the earthquake intensity and disaster losses in the aftermath of the Luding earthquake.The seismic intensity represents the distribution of earthquake disasters and the degree of ground damage and can be directly converted from the peak ground velocity(PGV)map.To obtain a reliable PGV distribution map of this earthquake,we combined the finite-fault model constrained by seismic observations,with the complex three-dimensional(3D)geological environment and topographical features to perform strong ground motion simulation.Then,we compared the consistency between the simulated ground motion waveforms and observations,indicating the plausibility and reliability of simulations.In addition,we transformed the PGV simulation results into intensity and obtained a physics-based map of the intensity distribution of the Luding earthquake.The maximum simulated intensity of this earthquake is IX,which is consistent with the maximum intensity determined from the postearthquake field survey.Based on the simulated seismic intensity map of the Luding earthquake and the earthquake disaster loss estimation model,we rapidly estimated the death and economic losses caused by this earthquake.The estimated results show that the death toll caused by this earthquake is probably 50-300,with a mathematic expectation of 89.Thus the government should launch a Level II earthquake emergency response plan.The economic losses are likely to be 10-100 billion RMB,with a mathematical expectation of 23.205 billion RMB.Such seismic intensity simulations and rapid estimation of disaster losses are expected to provide a preliminary scientific reference for governments to carry out the targeted deployment of emergency rescue and post-disaster reconstruction.

Assessing Potential Earthquake Loss in Me′rida State, Venezuela Using Hazus

The focus of the Hazus earthquake model has been largely U.S. centric due to a lack of standardized building-infrastructure data formats applicable elsewhere.In a combined effort between FEMA Region VIII and the Universidad de Los Andes, Venezuela, the present study uses the Hazus 2.1 software to simulate earthquake loss estimations for Venezuela. Population totals and demographic distributions were developed using Oak Ridge National Labs Landscan 2008 population data and the census 2011 for Venezuela. The accuracy of the model was further enhanced for Me′rida State, located in western Venezuela, by collecting, incorporating, and developing region and specific inventories including soil maps, liquefaction and landslide susceptibility studies, demographic data, and building inventory information. We used USGS Shake Maps scenarios for two potential earthquake events with peak ground accelerations proposed within Performance Based Seismic Engineering of Buildings, VISION 2000 recommendations. The region has not witnessed an earthquake with a magnitude greater than M 7 in the last120 years. Given the historical record of seismicity and the seismotectonics in the region, it becomes increasingly important to understand the potential implications from moderate to large earthquakes in Me′rida State, Venezuela.