Major river basins of the world

Source : UN Environment Programme

Major river basins of the world. Rivers form a hydrological mosaic, with an estimated 263 international river basins covering 45.3% of the land surface area of the earth, excluding Antarctica. This graphic shows the locations of 26 of the world’s major river basins. A basin is defined as the land area (watershed) where all surface water drains to a certain river.