Benue River, previously known as the Chadda River or Tchadda, is the major tributary of the Niger River. Almost its entire length of approximately 1,400 kilometres (870 mi) is navigable during the summer months. The size of its catchment basin is 319,000 km2 (123,000 sq mi). As a result, it is an important transportation route in the regions through which it flows. The name Benue comes from Binuwe meaning 'Mother of Waters’ in the Batta language.
Benue River
The River Benue looking south east from Jimeta.
Crossing the Benue River from Lagdo with a Canoe
A tributary, or an affluent, is a stream or river that flows into a larger stream, river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they flow, drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean.
Nam Khan flows into the Mekong at Luang Prabang in Laos.
At Harpers Ferry, West Virginia, looking downstream, the Shenandoah River (bottom right) meets the Potomac River, which flows from bottom left to top right, making the Shenandoah a right tributary of the Potomac.
The Mekong is a trans-boundary river, originating in the Tibetan Plateau. Its upper tributary river systems (e.g. ngom chu [zh]) are restricted to narrow gorges, but the tributaries that feed its lower reaches (e.g. the Mun River) cover larger areas.