Liquefaction Hazard Assessment

Liquefaction hazard assessment maps where earthquake-induced liquefaction is likely to occur and how severe its surface effects will be, across areas ranging from a city to a whole region. Unlike site-specific triggering analysis, which evaluates a single soil column from borehole data, regional assessment must predict liquefaction over wide areas where detailed subsurface data are sparse, so it relies on geospatial proxies for soil susceptibility together with a map of seismic demand. Zhu, Baise, and Thompson's 2017 geospatial model exemplifies the modern approach, predicting the probability of liquefaction from globally available variables such as slope-derived shear-wave velocity, a compound topographic index, and magnitude-adjusted peak ground acceleration, calibrated on documented liquefaction from past earthquakes. The Youd and Idriss 2001 consensus framework supplies the underlying site-scale physics and the severity indices that translate probability into expected damage. The product is a hazard map showing the spatial probability and intensity of liquefaction. It supports rapid post-earthquake response, loss estimation, and land-use planning where borehole-by-borehole analysis is infeasible.