Input layer sources

Layer themeDataset TitleProviderReference periodResolutionURL
ForestWRI Current forest coverageWorld Resources Institute (WRI) Atlas of Forest Landscape Restoration Opportunities2000-20090.008333 dd
MangrovesWCMC Global Distribution of Mangroves USGSWorld Conservation Monitoring Center (WCMC) Ocean Data Viewer1997-20000.00028 dd
SeagrassesWCMC Global Distribution of SeagrassesWCMC Ocean Data Viewer1934-20110.0004 dd
Coral reefsWCMC Global Distribution of Coral ReefsWCMC Ocean Data Viewer1954-20090.00028 dd

A 0.01-degree resolution raster of real area was generated for each of the four considered ecosystems using an equation that approximate Earth ellipsoid.

In the case of forest coverage, the initial WRI classification was grouped in three classes: woodland, open forest and closed forest. The final forest ecosystem percentage is based on the spatial sum of these three classes area.

The areas with a deforested status (“Potential forest lands that are currently non forest were assumed to be deforested”) were not included in these new classes.

Hazard exposure
Layer themeDataset TitleProviderReference periodResolutionURL
LandslidesFrequency of landslides triggered by earthquakesGAR 2009, PREVIEW / Global Risk Data PlatformModel0.008333 dd
LandslidesFrequency of landslides triggered by precipitationsGAR 2009, PREVIEW / Global Risk Data PlatformModel0.008333 dd
Tropical cyclonesTropical cyclones frequencyGAR 2013, PREVIEW / Global Risk Data Platform1970-20110.017333 dd
Tropical cyclones surgesTropical cyclones surge frequencyGAR 2009, PREVIEW / Global Risk Data Platform1975-20070.008333 dd
TsunamisTsunami hazard (tun up) RP 500 yearsGAR 2015, PREVIEW / Global Risk Data Platform500 years RP model0.008333 dd
River floodsFlood hazard # yearsGAR 2015, PREVIEW / Global Risk Data Platform25 to 1000 years RP model~0.01 dd

For each natural hazard, a 0.01-degree resolution raster was generated, illustrating hazard annual frequency weighted with portion of pixel potentially affected. Landslide hazard is separated in two categories: landslides triggered by earthquakes or rainfall. In our case, the final frequency raster is the sum of both hazard annual frequencies. The underlying hypothesis is that a pixel affected by an earthquake triggered landslide event could still be affected by a rainfall-triggered landslide event during the same year and somewhere else in the pixel.

In the case of cyclones, annual frequency raster is calculated using the Saffir-Simpson largest buffer of each event.

Physical exposure was calculated for each natural hazard multiplying the hazard frequency raster with the population raster. The flood hazard model has various return period layers, the final physical exposure is the sum of each single physical exposure.

Layer themeDataset TitleProviderReference periodResolutionURL
Population densityGHS Population gridJoint Research Center Data Catalogue20151 km


This work has been conducted jointly by UNEP and UNEP GRID-Geneva with funds from the European Union.




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