710 articles
Pechora
Pechora (Печора, Komi Печӧра) is a 1,809 km river in northern European Russia rising in the Northern Urals and flowing into the Barents Sea; it has the highest mean discharge of European Arctic rivers and a 322,000 km² coal, oil, and gas basin.
Pecos (landform)
Pecos River, also called Río Salado or Río Puerco, a major Rio Grande tributary rising in the Sangre de Cristo Mountains of New Mexico and flowing over 900 miles to Amistad Reservoir in Texas, draining about 44,000 square miles and known for high salinity.
Pecos (protected area)
The Pecos freshwater ecoregion is a conservation unit defined by the drainage basin of the Pecos River, extending from New Mexico into western Texas within the Rio Grande system.
Penner
Penner (Penna, Pennar; Pinākini) is a 597 km river of southern India rising at Nandi Hills, Karnataka, flowing through Andhra Pradesh to the Bay of Bengal; basin 55,213 sq km, rain-shadow, water-scarce, heavily dammed.
Peribonka
Peribonka (Rivière Péribonka) is a 547 km Quebec river, the largest tributary of Lake Saint-Jean, with a 28,200 km² basin, Alcan and Hydro-Québec dams including a 405 MWe plant, and a namesake village tied to Maria Chapdelaine.
Pinega
The Pinega (Пинега) is a 779 km river in Arkhangelsk Oblast, northern Russia, and a right tributary of the Northern Dvina with a 42,600 km² basin.
Ping
Ping River (Mae Ping, แม่น้ำปิง), 740-km Thai river rising in Chiang Mai and joining the Nan at Nakhon Sawan to form the Chao Phraya; 33,898 km² basin, Bhumibol Dam (1964), ~300-year floodplain-stripping cycle.
Platte River
The Platte River, formed by the North and South Platte in Nebraska, is a braided Great Plains river flowing to the Missouri. Known for sandhill crane staging, whooping crane critical habitat, and Colorado-Nebraska water disputes.
Po (river)
Po (landform): Italy's longest river, 652-661 km, rising at Monte Viso and flowing to the Adriatic near Venice; nine-branch delta, about 1,500 m3/s mean discharge, heavily managed and drought-prone.
Pollution of the Ganges
Pollution of the Ganges: contamination of India's Ganga river by untreated sewage (over 80% of load), industrial effluent, and runoff, addressed since the 1985 Ganga Action Plan and the 2014 Namami Gange Programme, with persistent capacity and utilization gaps.
Pool
Pool: a deep, slow-water topographic low in a riverbed alternating with riffles every 3–5 channel widths; formed by flow obstructions or free-formed scour; also oil-and-gas reservoirs and marsh pools.
Potomac River
The Potomac River is a 400-mile mid-Atlantic river flowing to Chesapeake Bay, supplying 80 percent of Washington, DC's drinking water, site of the 2026 Potomac Interceptor sewage spill.
Puerto Rico - Virgin Islands
Puerto Rico - Virgin Islands (FEOW ID 215) is a freshwater ecoregion of the Freshwater Ecoregions of the World framework, covering rivers of Puerto Rico, the Virgin Islands, and the British Virgin Islands, habitat type tropical and subtropical coastal rivers.
Pur
Pur (Пур), river in Yamalo-Nenets Autonomous Okrug, Russia; formed by the Pyakupur and Aivasedapur, flows 389 km (1,024 km with Pyakupur) north into Tazovskaya Guba, Kara Sea; basin 112,000 km², discharge 884 m³/s, navigable, gas-producing region.
Purus
Purus (Rio Purus), major whitewater tributary of the Amazon/Solimoes rising in Peru, about 3,380 km long, basin 375,458 km2, discharge ~8,500 m3/s; only major Amazonian tributary with an undammed watershed.
Putumayo
The Putumayo River, called the Içá in Brazil, is a roughly 1,600 km Amazon tributary rising in the Colombian Andes and draining parts of Colombia, Ecuador, Peru, and Brazil.
Pyasina
Pyasina (Пясина), Arctic river in Krasnoyarsk Krai, Russia: 818 km from Lake Pyasino across the Taymyr Peninsula to Pyasina Bay of the Kara Sea; 182,000 km² basin, 354 km tidal reach, Norilsk-linked history.
Qaidan
Qaidan (FEOW ecoregion 632) is a Palearctic freshwater ecoregion of temperate upland rivers in the Qaidam Basin, northeastern Tibetan Plateau, China, delineated by The Nature Conservancy and WWF (2008).
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.
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 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.
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.
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.
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.
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.
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 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.