710 articles
Rio Negro (Brazil)
Rio Negro (Brazil): the world's largest blackwater river, a 2,250 km Amazon tributary joining the Amazon at Manaus; acidic nutrient-poor tannin-dark water, ~28,000 m3/s discharge, over 90 endemic fish species, record 2023 drought low.
Río Negro (Paraguay)
Río Negro (Paraguay): river in the Paraguayan Pantanal, Alto Paraguay, whose 370,000-ha Ramsar site no. 729 (designated 1995) and Río Negro National Park protect a Pantanal-Chaco-Cerrado ecotone with giant otters and jaguars.
Rio Pongo
Rio Pongo: river and estuarine Ramsar Site no. 574 in Boké/Boffa, western Guinea, designated 18 November 1992, 600,571 ha of pristine mangrove and mudflats, home to waterbirds and the African manatee.
Río Sabinas
Río Sabinas (Ramsar site 1769) is a perennial river in northeastern Coahuila, Mexico, rising in the Sierra de Santa Rosa and joining the Río Salado at Don Martín dam; 603,123 ha, sabino cypress forests, mining and wastewater pressures.
Rio Salado
Rio Salado (Spanish, "Salt River") names several rivers: a Rio Grande tributary in northeastern Mexico (FEOW ecoregion 137), a Santa Fe Province river in Argentina, a New Mexico Rio Grande tributary, Arizona's Salt River, and a Chilean Atacama priority site.
Rio San Juan (Mexico)
Rio San Juan (Río San Juan), northeastern Mexican tributary of the Rio Grande rising in the Sierra Madre Oriental; 34,000 km² watershed, El Cuchillo and Marte R. Gómez dams, FEOW ecoregion 138, Endangered status, Monterrey water transfers.
Rio Santiago
Río Santiago (Río Grande de Santiago), western Mexico river draining Lake Chapala 563 km to the Pacific past Guadalajara; among Mexico's most polluted, with four reaches and an active restoration strategy.
Rio Tuira
Rio Tuira (Río Tuira), a 127-km river in Darién, Panama, rising in the Sierranía del Darién and flowing 3,017 km² basin to the Golfo de San Miguel; main transport artery, 82.1 m³/s mean flow, fourteen endemic fishes in its ecoregion.
Riparian zone
Riparian zone: land alongside rivers, streams, lakes, and wetlands shaped by their hydrology, transitional between wetland and upland. Vegetated buffers there trap sediment and remove 12–80% of nitrogen; biodiversity needs far wider corridors than water quality.
River
River: a natural freshwater stream flowing in a definite channel toward sea, lake, or another river. Also drainage-basin runoff, meandering vs braided channels, discharge measurement, and global drying trends.
River basin development
River basin development: planned multipurpose management of an entire drainage basin (flood control, irrigation, hydropower, water supply), from the 1933 Tennessee Valley model and Japan's 1953 Kitakami program to modern cumulative-impact and transboundary planning.
River Clyde
The River Clyde, also known as the Clyde or Abhainn Chluaidh, is a river in western Scotland that flows through Glasgow to the Firth of Clyde.
River Irwell
River Irwell: Pennine-source river in Lancashire and Greater Manchester, flowing through Manchester and Salford into the Manchester Ship Canal. Once among Europe's most polluted rivers; now recovering, with flood schemes and the 8 km Irwell River Park.
River Island
River island (riverine island): land surrounded on all sides by river channels, formed by sediment deposition in braided or meandering rivers; examples include Majuli and Tianxingzhou on the Yangtze; distinct from the Falklands' saltwater River Island.
River Mersey
River Mersey, North West England river flowing through Manchester into the Mersey Estuary at Liverpool; famed as one of Europe's most polluted rivers, later restored via the 1985 Mersey Basin Campaign, with salmon returning and 2025 flood repairs.
River restoration
River restoration is the set of activities that modify channels, floodplains, and water and sediment inputs to improve degraded rivers' hydrologic, geomorphic, and ecological processes.
River Ribble
The River Ribble is a 110 km river in northern England that rises in the Western Pennines and flows into the Irish Sea west of Preston.
River Severn
River Severn (Afon Hafren), longest river in Great Britain at 354 km, rising at Plynlimon in Wales and flowing to the Severn Estuary; supplies 6 million people, navigable Stourport to Avonmouth, regulated by Clywedog reservoir.
River Shannon
River Shannon (Abhainn na Sionainne), longest river in the British Isles at about 340 km, draining some 15,000 km2 of Ireland through Loughs Allen, Ree and Derg to the Shannon Estuary; home of Ardnacrusha hydro station, a major navigation, and the Parteen Basin abstraction project to Dublin.
River Spey
The River Spey is a major Scottish river rising at Loch Spey in the Monadhliath Mountains, flowing 170 km northeast to the Moray Firth at Spey Bay; seventh-largest in Britain, famed for salmon fishing and Speyside whisky.
River Taff
River Taff (Taf), South Wales river about 64 km long, formed by the Taf Fechan and Taf Fawr at Merthyr Tydfil, flowing through Pontypridd to Cardiff Bay; historic coal-and-iron artery, now managed for flood risk, water quality, and hydropower.
River Thames
The River Thames is a 210-mile English river rising in the Cotswolds and flowing through Oxford and London to the North Sea. Tidal through London with over 7 m spring range, defended by the Thames Barrier, and served by the debt-laden Thames Water utility.
River Torrens
River Torrens (Karrawirra Pari), Adelaide's main river: 85 km from the Mount Lofty Ranges to the sea at West Beach, named by Light in 1836, dammed in 1881 to form Torrens Lake, with highly modified regulated flows.
River Trent
The River Trent is England's third longest river, rising near Stoke-on-Trent and running about 271 km to the Humber Estuary. Navigable from Shardlow, tidal below Cromwell Lock with the aegir bore, it drains 10,450 km2 of the industrial Midlands and supplies about half the Humber's freshwater.
River water
River water is the water carried downhill in a stream bed toward a lake or ocean, supplying drinking water, irrigation, hydropower, transport, and habitat for people and ecosystems.
River Wharfe
River Wharfe: Yorkshire river rising in the Yorkshire Dales National Park, flowing through Wharfedale to the Ouse. Historic Tadcaster navigation; UK's first river bathing water at Ilkley (2020).
Rivers of Ireland
Rivers of Ireland: over 73,000 km of channels, with the Shannon the longest at more than 360 km. Covers major rivers, EPA hydrometric monitoring, flow regimes, water quality status, and River Basin Management.
Rivers of Jamaica
Jamaica's rivers are more than 100 short, steep, fast-flowing streams organized into 10 hydrological basins and 26 Watershed Management Units; the Rio Minho, at 92.5 km, is the longest.
Roanoke River
Roanoke River: roughly 400-mile Virginia-North Carolina river, also called Moratoc, flowing from the Blue Ridge to Albemarle Sound, dammed by Kerr, Gaston, Roanoke Rapids, and Smith Mountain projects.
Rubicon
The Rubicon (Rubicone, Latin Rubico) is a small Romagna river, about 40 km long, that marked the Italy-Cisalpine Gaul border; Julius Caesar crossed it with the 13th Legion on 10 January 49 BC, starting the civil war. Its ancient course is disputed between the Fiumicino, Pisciatello, and Uso, with official identification in 1933.