Gridded Population of the World, Version 4 (GPWv4): Land and Water Area, Revision 11

The Gridded Population of the World, Version 4 (GPWv4): Land and Water Area, Revision 11 consists of two rasters that measure surface areas of land and water in square kilometers per pixel. The Land Area raster provides estimates of the land area, excluding permanent ice and water, within each pixel, and was used to calculate the population density rasters. The Water Area raster provides estimates of the water area (permanent ice and water) within each pixel. The sum of land area and water area of a pixel equals the total surface area of that pixel. The data files were produced as global rasters at 30 arc-second (~1 km at the equator) resolution. To enable faster global processing, and in support of research commUnities, the 30 arc-second data were aggregated to 2.5 arc-minute, 15 arc-minute, 30 arc-minute and 1 degree resolutions.

《世界网格人口，版本4（GPWv4）：陆地与水域，修订11版》包含两个栅格，分别用于衡量每像素的陆地和水域面积，单位为平方千米。陆地面积栅格提供每个像素内陆地面积的估计值，不包括永久性冰雪和水面，并据此计算出人口密度栅格。水域面积栅格提供每个像素内水域面积（包括永久性冰雪和水面）的估计值。像素的陆地面积与水域面积之和等于该像素的总表面积。数据文件以全球栅格形式生成，分辨率为30弧秒（赤道附近约为1千米），以支持全球范围内的快速处理，并满足研究群体的需求，30弧秒的数据被汇总至2.5弧分、15弧分、30弧分和1度分辨率的级别。