Input layer sources
Ecosystems
Layer theme | Dataset Title | Provider | Reference period | Resolution | URL |
Forest | WRI Current forest coverage | World Resources Institute (WRI) Atlas of Forest Landscape Restoration Opportunities | 2000-2009 | 0.008333 dd | https://www.wri.org/applications/maps/flr-atlas/# |
Mangroves | WCMC Global Distribution of Mangroves USGS | World Conservation Monitoring Center (WCMC) Ocean Data Viewer | 1997-2000 | 0.00028 dd | https://data.unep-wcmc.org/ |
Seagrasses | WCMC Global Distribution of Seagrasses | WCMC Ocean Data Viewer | 1934-2011 | 0.0004 dd | https://data.unep-wcmc.org/ |
Coral reefs | WCMC Global Distribution of Coral Reefs | WCMC Ocean Data Viewer | 1954-2009 | 0.00028 dd | https://data.unep-wcmc.org/ |
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 theme | Dataset Title | Provider | Reference period | Resolution | URL |
Landslides | Frequency of landslides triggered by earthquakes | GAR 2009, PREVIEW / Global Risk Data Platform | Model | 0.008333 dd | https://preview.grid.unep.ch |
Landslides | Frequency of landslides triggered by precipitations | GAR 2009, PREVIEW / Global Risk Data Platform | Model | 0.008333 dd | https://preview.grid.unep.ch |
Tropical cyclones | Tropical cyclones frequency | GAR 2013, PREVIEW / Global Risk Data Platform | 1970-2011 | 0.017333 dd | https://preview.grid.unep.ch |
Tropical cyclones surges | Tropical cyclones surge frequency | GAR 2009, PREVIEW / Global Risk Data Platform | 1975-2007 | 0.008333 dd | https://preview.grid.unep.ch |
Tsunamis | Tsunami hazard (tun up) RP 500 years | GAR 2015, PREVIEW / Global Risk Data Platform | 500 years RP model | 0.008333 dd | https://preview.grid.unep.ch |
River floods | Flood hazard # years | GAR 2015, PREVIEW / Global Risk Data Platform | 25 to 1000 years RP model | ~0.01 dd | https://preview.grid.unep.ch |
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.
Population
This work has been conducted jointly by UNEP and UNEP GRID-Geneva with funds from the European Union.
