The Low Elevation Coastal Zone collection includes three data sets: the Urban-Rural Population Estimates, v1 (1990, 1995, 2000), the Urban-Rural Population and Land Area Estimates, v2 (1990, 2000, 2010, 2100), and the Sea Level Rise Impacts on Ramsar Wetlands of International Importance, v1 (2000 – 2010). Users are encouraged to review the methodologies used for constructing these data sets and to acknowledge uncertainties and limitations.
Country-level estimates of urban, rural and total population and land area in LECZ’s were generated globally using Global Rural-Urban Mapping Project (GRUMP) population and land area data products. The Urban-Rural Population Estimates, v1 (1990, 1995, 2000) data set uses GRUMP alpha data and was estimated at a 1km (30 arc second) grid resolution. The Urban-Rural Population and Land Area Estimates, v2 (1990, 2000, 2010, 2100) dataset used GRUMP v1 population inputs and urban-rural data, and is estimated at a ~90m (3 arc second) grid resolution to conform with the native resolution of the elevation data. The GRUMP data were also used at a 1km (30 arc second) grid resolution in order to reflect uncertainty levels in the product resulting from the interplay of input population data resolutions (based on census units) and the elevation data. This data set also reconciled the coastal boundaries using ISciences LLC’s coastal boundary data set in order to reduce the possibility of spatial mismatches. Both datasets are based on a Digital Elevation Model (DEM) derived from NASA Shuttle Radar Topographic Mission (SRTM) data. The low elevation coastal zones were derived from the DEM by selecting all land areas contiguous to the coast below 20m elevation. Estimates of population (head counts and percents) and land areas (square kilometers and percents) were generated for urban, rural and total locations for each country as a whole and within the LECZs.
Sea Level Rise Impacts on Ramsar Wetlands of International Importance, v1 (2000 – 2010) provides estimates of the area and percent area of coastal Ramsar wetland sites that would become inundated under 1 and 2 meter sea level rise scenarios.