List of Longest Rivers in the World

Measuring the length of a river sounds simple, but it is one of the great unresolved questions of geography. The traditional crown belongs to the Nile at roughly 6,650 kilometres, a figure taught in schools for more than a century. But a Brazilian-Peruvian expedition in 2007 traced a source of the Amazon high in the Peruvian Andes and argued that it should now be considered the longest river in the world, at around 7,000 kilometres. The debate is still alive, and different authoritative sources give different answers. What is not in dispute is the scale of these rivers. The Amazon carries about one-fifth of all freshwater that flows into the oceans from the entire planet. The Yangtze, Asia's longest, cuts through the most populous river valley on Earth. The Mississippi–Missouri system drains 40 percent of the contiguous United States. Every one of the world's ten longest rivers has been, at some point, a cradle of civilisation — the Nile of ancient Egypt, the Yangtze and Yellow of imperial China, the Indus of the Harappans. These rivers are also among the most dammed and most engineered waterways in history. China's Three Gorges Dam on the Yangtze is the largest hydroelectric power station in the world. Egypt's Aswan High Dam reshaped the entire lower Nile. The environmental trade-offs — displaced communities, collapsed fisheries, silt trapped behind concrete — are a central topic of 21st-century water policy. Climate change is now quietly rewriting these lists. Glacial sources in the Himalayas and the Andes are retreating, altering the upstream flow of the Yangtze, the Ganges, and the Amazon. Droughts have shrunk the Rhine and the Congo in recent summers. The rankings below are stable for now, but the rivers themselves are not.