2,436 articles
Riiser-Larsen Ice Shelf embayments of the Weddell margin
The Riiser-Larsen Ice Shelf embayments of the Weddell margin are coastal indentations along Antarctica's Weddell Sea, notably Vahsel Bay, charted in 1912, and the Lassiter Coast.
Ring of Fire
Ring of Fire (Pacific Ring of Fire): popular name for the circum-Pacific belt of subduction-zone volcanoes and earthquakes, not a scientific term. Holds 687 Holocene volcanoes (57% of world total) and about 81% of the largest earthquakes; first named by Carl Ritter in 1859.
Ringkøbing Fjord
Ringkøbing Fjord, a ~300 km² shallow brackish coastal lagoon on Denmark's west coast, cut off from the North Sea by Holmsland Klit and regulated since 1931 by the Hvide Sande sluice; Ramsar and Natura 2000 site famed for waterbirds and Tipperne reserve.
Rio
Rio (Spanish río, Portuguese rio) means river, from Latin rivus. The word names Rio de Janeiro, the Rio Grande (Río Bravo del Norte), the Rio Negro, and stewardship programs like Guardiões dos Rios.
Rio Conchos
Río Conchos: principal Mexican tributary of the Rio Grande (Río Bravo), rising in the Sierra Tarahumara, Chihuahua; dammed at La Boquilla (1914), treaty-shared with the US, and a freshwater endemism hotspot.
Río de la Plata
Río de la Plata (River Plate): funnel-shaped microtidal estuary between Argentina and Uruguay, 300 km long and up to 220 km wide, draining the Paraná and Uruguay rivers into the South Atlantic; one of the world's most turbid estuaries.
Rio Grande
Rio Grande, or Río Bravo del Norte, is a major North American river rising in Colorado's San Juan Mountains, flowing about 1,900 miles to the Gulf of Mexico and forming the US-Mexico border from El Paso to the Gulf.
Rio Grande Rise
Rio Grande Rise: large submerged volcanic plateau in the SW Atlantic, ~1,000-1,200 km off Brazil, conjugate of the Walvis Ridge, formed by 30+ Myr of Tristan-Gough plume-ridge interaction, with ferromanganese crusts of critical minerals.
Rio Juruá
Rio Juruá: a ~3,500 km meandering tributary of the Solimões (Amazon) River in western Brazil, and Ramsar Site no. 2362 (designated 29 September 2018, 2,136,489 ha), a várzea floodplain with 392 fish species, threatened mammals, and community-managed pirarucu fisheries.
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.