Global Human Settlement Layer: Population and Built-Up Estimates, and Degree of Urbanization Settlement Model Grid

The Global Human Settlement Layer: Population and Built-Up Estimates, and Degree of Urbanization Settlement Model Grid data set provides gridded data on human population (GHS-POP), built-up area (GHS-BUILT), and degree of urbanization (GHS-SMOD) across four time periods: 1975, 1990, 2000, and 2014 (BUILT) or 2015 (POP, SMOD). GHS-BUILT describes the percent built-up area for each 30 arc-second grid cell (approximately 1 km at the equator) based on Landsat imagery from each of the four time periods. GHS-POP consists of census data from the 2010 round of global census from Gridded Population of the World, Version 4, Revision 10 (GPWv4.10) spatially-allocated within census units based on the percent built-up areas from GHS-BUILT. GHS-SMOD uses GHS-BUILT and GHS-POP in order to develop a standardized classification of degree of urbanization grid. The original data from the Joint Research Centre of the European Commission (JRC-EC) has been combined into a single data package in GeoTIFF format and reprojected from Mollweide Equal Area into WGS84 at 9 arc-second and 30 arc-second horizontal resolutions in order to support integration with a variety of global raster data sets.
To provide global data on human population, built up area, and degree of urbanization for the years 1975, 1990, 2000, and 2014/2015 in the World Geodetic System 1984 (WGS84) geographic coordinate system.

全球人类住区图层：人口与建成区估算及城市化程度住区模型网格数据集，提供覆盖四个时段的栅格数据：包括1975年、1990年、2000年，以及2014年（适用于建成区栅格数据GHS-BUILT）或2015年（适用于人类人口栅格数据GHS-POP与城市化程度栅格数据GHS-SMOD）的人类人口、建成区与城市化程度栅格数据。其中，GHS-BUILT基于对应四个时段的陆地卫星（Landsat）影像，刻画每个30角秒栅格单元（赤道处约合1公里）的建成区占比；GHS-POP以GHS-BUILT的建成区占比为空间分配依据，将源自《世界栅格人口数据第四版第十次修订版（GPWv4.10）》2010年全球普查的普查人口数据空间分配至各普查单元中；GHS-SMOD则结合GHS-BUILT与GHS-POP数据，构建标准化的城市化程度栅格分类体系。该数据集原始数据源自欧盟委员会联合研究中心（JRC-EC），现已整合为GeoTIFF格式的单一数据包，并从摩尔魏特等面积投影（Mollweide Equal Area）重投影至世界大地测量系统1984（WGS84）坐标系，提供9角秒与30角秒两种水平分辨率，以支持与各类全球栅格数据集的集成对接。
本数据集旨在提供1975年、1990年、2000年及2014/2015年的全球人类人口、建成区与城市化程度数据，坐标系采用世界大地测量系统1984（WGS84）地理坐标系。