New data from the US Geological Survey (USGS) indicates that Hurricane Maria resulted in a significant number of landslides in the mountainous regions of Puerto Rico.
The USGS has published a map of Puerto Rico showing the landslide impact of the category 4 Hurricane Maria which passed the island on 20 September.
USGS used post-hurricane satellite and aerial imagery to visually estimate the concentration of landslides over nearly the whole territory.
The analysis was undertaken on a 4km2 grid pattern and classified each square as containing no landslide, fewer than 25 landslides or more than 25 landslides.
“We identified landslides by locating areas with exposed soil or rock and morphology typical of landslides,” said a spokesman for the USGS. “Because leaves were stripped from much of the vegetation, landslide scars were readily visible in both sources of imagery.
“We assume that the majority of landslides were triggered by rainfall from Hurricane Maria, but rainfall from Hurricane Irma during the first week of September and rainfall from thunderstorms after Hurricane Maria may have also initiated landslides.”