Scenario-based seismic vulnerability and hazard analyses to help direct disaster risk reduction in rural Weinan, China

Abstract

Seismic vulnerability and hazard analyses play a significant role in comprehensive risk mitigation and seismic emergency planning, especially for the rural Weinan prefecture in northwestern China with a complex construction infrastructure and a high population density. Traditional methods assessing potential physical seismic damage prior to an earthquake are providing an incomplete picture for seismic risk assessments and post-disaster situations, and are insufficient for local authorities to plan mitigation strategies effectively. This study presents a novel perspective on scenario-based seismic vulnerability and hazard assessment. First, an in situ survey was carried out in three villages, Helan, Zhaojia, and Dongyu Village in the plain, loess, and mountain area respectively. Then, a quantitative analysis of building vulnerability and associated human homelessness under different seismic intensities was conducted based on the RISK-UE vulnerability index method. Finally, we estimated and analyzed other seismic impact scenarios. Results showed that the mean building vulnerability index is 0.69, 0.70, and 0.76 for Helan, Zhaojia, and Dongyu Village, respectively. Considering the possible displaced populations, Dongyu Village will have the highest proportion of homeless people. If an earthquake causes intensity greater than VII, Dongyu Village would suffer landslides and isolated-communication. The residents would have to rely on self-rescue and mutual rescue. These findings can be a potential guide to decision making in disaster risk reduction in rural Weinan.