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

The Gridded Population of the World, Version 4 (GPWv4): Land and Water Area Grids measure surface areas in square kilometers. The land area grid provides estimates of the land area, excluding permanent ice and water, within each pixel. The water area grid 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.

世界栅格人口第四版（Gridded Population of the World, Version 4，GPWv4）：陆地区域与水域栅格数据集，以平方千米为单位量测地表面积。其中，陆地区域栅格用于估算每个像元内排除永久冰雪与水域后的陆地区域面积；水域栅格用于估算每个像元内的永久冰雪与水域面积。单个像元的陆地区域面积与水域面积之和，等于该像元的总地表面积。