2,436 articles
Rainwater Basin Wetland Management District
The Rainwater Basin Wetland Management District, formerly Hastings Wetland Management District, is a U.S. Fish and Wildlife Service unit protecting playa wetlands in south-central Nebraska.
Rainy (lake)
Rainy Lake, a 360 sq mi (932 km2) border lake of northern Minnesota and southwestern Ontario, mostly within Voyageurs National Park, draining to the Rainy River, dam-regulated under IJC rule curves since 1949.
Ramsar Convention
Ramsar Convention (Convention on Wetlands of International Importance especially as Waterfowl Habitat): 1971 treaty for wetland conservation and wise use, in force 1975, UNESCO depositary, Ramsar List sites, nine criteria, COP15 2025 Victoria Falls.
Randijaure
Randijaure (Ráddnávrre) is a 51 km² regulated lake in Jokkmokk Municipality, Norrbotten, Sweden, on the Lilla Luleälven; oligotrophic, max depth 31 m, reservoir of the Randi hydropower station built from 1973.
Ranganathittu Bird Sanctuary
Ranganathittu Bird Sanctuary, also called Pakshi Kashi of Karnataka, is a Ramsar wetland of islets on the Cauvery River near Srirangapatna, Mandya district. Established in 1940 on Salim Ali's advice, it hosts about 170 bird species, nesting painted storks, and mugger crocodiles.
Rann of Kutch
The Rann of Kutch is a large saline salt marsh in Gujarat, India, extending into Pakistan's Sindh, divided into the Great and Little Rann, flooded each monsoon, a major salt-producing region, and the site of the 1965 India-Pakistan clash settled by the 1968 boundary arbitration.
Rappahannock River
Rappahannock River: Virginia river rising at Chester Gap, flowing about 184 miles to the Chesapeake Bay; 2,715 sq mi watershed, fall line at Fredericksburg, State Scenic upper 62 miles.
Raystown Lake
Raystown Lake: 8,300-acre US Army Corps of Engineers reservoir on the Raystown Branch of the Juniata River in Huntingdon and Bedford Counties; Pennsylvania's largest lake entirely within the state, dam built 1968-1973.
Red (river)
Red River (Sông Hồng, Sông Cái), a 1,100 km river rising in Yunnan, China, flowing through northern Vietnam to the Gulf of Tonkin; steep, flood-prone, heavily dammed, and central to the diked Red River Delta around Hanoi.
Red (レット湖)
Red Lake (レット湖): Upper and Lower Red Lake, Minnesota's largest inland lake at 288,800 acres, mostly within the Red Lake Indian Reservation, famed for a walleye fishery that collapsed in the 1990s and reopened in 2006.
Red River of the North
Red River of the North (rivière Rouge du Nord): 550-mile north-flowing river from Breckenridge, Minnesota to Lake Winnipeg, forming the Minnesota–North Dakota border on the flat glacial Lake Agassiz bed, historically a fur-trade route and subject to major floods such as 1997 and 2009.
Red River of the South
Red River of the South: a 1,360-mile river rising in New Mexico, flowing along the Texas-Oklahoma border to the Mississippi; also called Rio Rojo, marked by red flood soils, saline water, and long boundary disputes.
Red River Valley
The Red River Valley, also known as the Red River Basin, is the flat valley of the north-flowing Red River along the North Dakota-Minnesota boundary, prone to spring flooding.
Reed (plant)
Reed (Phragmites australis), common reed, is a cosmopolitan rhizomatous wetland grass with culms 1–4(–6) m. Native lineages and an invasive European haplotype (M) coexist in North America; it tolerates moderate salinity via leaf osmotic adjustment.
Reed bed
Reed bed: wetland dominated by common reed (Phragmites australis), over 60% cover. Covers natural fen habitat, rare in Britain, and engineered reed bed systems for wastewater and sludge treatment since 1985.
Reelfoot Lake
Reelfoot Lake is a shallow natural lake in northwestern Tennessee, the state's largest natural lake at 10,427 acres, formed by subsidence during the February 1812 New Madrid earthquake.
Reichenbach Falls
Reichenbach Falls (Reichenbachfälle) are a seven-tiered, roughly 250 m waterfall above Meiringen, Switzerland, fed by Rosenlaui Glacier meltwater, served by the 1899 Reichenbachfall-Bahn funicular, and famous as Sherlock Holmes's apparent death site in Conan Doyle's 1893 "The Final Problem".
Revelle Inlet
Revelle Inlet, also Revelle Bay or Revelle, Ensenada, is an ice-filled inlet on the Wilkins Coast of Palmer Land, Antarctic Peninsula, at about 68°40'S 63°26'W, bounded by Cape Keeler and feeding flow units of the Larsen C Ice Shelf.
Reykjanes Ridge
The Reykjanes Ridge is the roughly 900 km section of the Mid-Atlantic Ridge running from Iceland to the Bight Fracture Zone, separating the North American and Eurasian plates.
Rheic Ocean
The Rheic Ocean was a Paleozoic ocean basin between Gondwana and Laurussia, opened about 490 Ma when Avalonia rifted from Gondwana, and closed in the Devonian–Carboniferous, producing the Variscan and Alleghanian orogenies and helping assemble Pangaea.
Rhine
The Rhine (Rhein, Rhin, Rijn) is a major western European river from the Swiss Alps to the North Sea. Distinguished by the 1815 CCNR free-navigation regime, Tulla's rectification, Rhine 2040 water quality targets, and 2026 record-low drought flows.
Rhine Falls
Rhine Falls (Rheinfall), waterfall on the Rhine near Schaffhausen, Switzerland; Europe's largest waterfall by volume, not height: 23 m high, 150 m wide, about 600 m³/s in summer, record 1,250 m³/s in 1965.
Rhône
The Rhône (Rhone) is an 812 km Alpine river from the Swiss Valais through Lake Geneva to the Mediterranean, France's most powerful river at 1,700 m3/s, heavily dammed for hydropower, navigation, and irrigation, and now under major restoration.
Ria
A ria is a drowned, unglaciated river valley flooded by the sea, forming a branching rocky-coast inlet; term coined by von Richthofen (1886) from Galicia's rias, distinct from glacial fjords, found worldwide.
Ría de Vigo
The Ría de Vigo is the southernmost of Galicia's four Rías Baixas, a roughly 33 km sea inlet in Pontevedra province on Spain's Atlantic coast.
Rías Baixas
The Rías Baixas are four large, funnel-shaped coastal inlets on the western coast of Galicia, north-west Spain, whose seasonal Atlantic upwelling drives highly productive waters supporting fisheries and mussel farming.
Ribeira de Iguape
The Ribeira de Iguape is a river in southeastern Brazil, rising in Paraná and flowing about 470 km to the Atlantic at Iguape, on the São Paulo coast.
Rice Lake (Ontario)
Rice Lake is a warm, shallow lake in southern Ontario, about 30 kilometers long, named for the wild rice that once grew there and home to the ancient Serpent Mounds.
Richard Collinson Inlet
Richard Collinson Inlet, a large shallow inlet on the north coast of Victoria Island, Nunavut, between Barnard Point and Loch Point; named for Arctic explorer Sir Richard Collinson, with ringed seals and spring polar bear habitat.
Richards Bay
Richards Bay, KwaZulu-Natal, South Africa: deep-water port on the Mhlatuze Lagoon, opened 1 April 1976 for coal export, home to the Richards Bay Coal Terminal and South Africa's largest port by tonnage.