A global dataset and model of earthquake-induced landslide fatalities

  • PDF / 3,504,026 Bytes
  • 14 Pages / 595.276 x 790.866 pts Page_size
  • 94 Downloads / 154 Views

DOWNLOAD

REPORT


M. Anna Nowicki Jessee I M. W. Hamburger I M. R. Ferrara I A. McLean I C. FitzGerald

A global dataset and model of earthquake-induced landslide fatalities

Abstract In this study, we present a newly developed, comprehensive dataset of 196 historical earthquakes, including 127 events with known landslide fatality counts, which we use to examine the impact of earthquake-induced landslides. Using this dataset, we assess the potential impact of seismically induced landslides on affected populations, based on the exposure of population to expected landslide occurrence. We calculate predicted landslide probabilities out of a global statistical landslide model in the area surrounding each earthquake using USGS’s ShakeMap model of strong ground motion. We identify estimated population exposure by comparing the predicted probability grid with a timecorrected global population dataset to determine a predicted landslide exposure index. We compare these values to the number of actual fatalities for 91 training events and use these comparisons, together with the United Nations Human Development Index as a vulnerability proxy, to develop a multiple regression model that can potentially be used to provide order-of-magnitude estimates of human impact of earthquake-induced landslides. We observe a significant positive correlation between predicted and observed fatalities, but with very high variability in fatality rates for similar exposure levels, suggesting that other factors (e.g., landslide type and density, the effect of urbanization on population exposure) should be used to improve this estimate. We also demonstrate that these estimates of landslide impacts can be used in a deterministic mode, in collaboration with use of scenario earthquakes, to assess the potential impacts of anticipated future events. With further development, these landslide scenarios can be used by vulnerable communities to improve land use planning, structural design, and emergency response in landslide-prone areas. Keywords Landslides . Earthquakes . Earthquakeinduced . Hazards . Fatalities . Empirical Introduction Earthquake-induced landslides can have significant impacts on the populations affected by damaging earthquakes, ranging from 5% (Marano et al. 2009) to 11% (Daniell et al. 2017) of all earthquake-related fatalities. While this is a modest percentage, the estimation of Marano et al. (2009) is equivalent to about 71,000 fatalities between 1968 and 2008. In addition to these studies, Bird and Bommer (2004) also disaggregated losses due to ground failure from primary losses due to ground shaking. They observed that landslides were the primary cause of damage in 37% of earthquakes that had transportation disruption/ damage and 6% of earthquakes that had damage to buildings. Budimir et al. (2014) modeled fatalities due to both earthquakes and earthquake-induced landslides, showing that earthquakes that caused landslides typically caused more fatalities (a cascading hazard) than those without landslides. Their study developed a linear statistical m