710 articles
Shatt al-Arab (شط العرب)
Shatt al-Arab (شط العرب), also Arvand Rud, is the Tigris-Euphrates confluence river flowing to the Persian Gulf along the Iran-Iraq border, defined by the 1975 Algiers thalweg boundary, the 1980-88 war, and severe Basra salinity intrusion.
Shebelle (river, Somalia)
Shebelle River (Webi Shabeelle), longest river in eastern Ethiopia at over 1,000 km, rises in the Ethiopian highlands, flows into Somalia toward the Arabian Sea, over 90% of discharge from highland runoff, often dries in lower reaches.
Shenandoah River
The Shenandoah River is a Potomac tributary formed at Front Royal, Virginia, by the North and South Forks, flowing 57 miles to Harpers Ferry; a top eastern smallmouth bass river with fish kills and harmful algal blooms.
Shilka (Amur)
Shilka (Amur) is FEOW freshwater ecoregion 619, a Palearctic temperate upland rivers ecoregion covering the Shilka River drainage in Russia and Mongolia, with one endemic fish.
Sierra Madre del Sur (protected area)
Sierra Madre del Sur, FEOW freshwater ecoregion 170 (not a formal protected area), Neotropic coastal rivers of Guerrero and Oaxaca, Mexico, draining Pacific slopes of the Sierra Madre del Sur; major rivers Petatlán, Papagayo, Verde, Colotepec.
Sitang - Irawaddy
Sitang - Irawaddy (FEOW ecoregion 720) is a freshwater ecoregion covering Myanmar's Sittang and Ayeyarwady (Irrawaddy) basins, a tropical floodplain-river habitat with 62 recorded endemic fish species and the critically endangered Ayeyarwady Irrawaddy dolphin.
Skeena
Skeena (Skeena River, Tsimshian K'shian), British Columbia's second-largest river, flows about 580 km from northwestern BC to Chatham Sound near Prince Rupert; a major salmon and steelhead watershed with 66 salmon Conservation Units.
Snake River
Snake River, largest tributary of the Columbia River, rises in Yellowstone's Two Ocean Plateau, flows through Wyoming, Idaho, and Washington. Named for the Shoshone by 1812; 22 dams, four contested lower-Snake dams, and threatened salmon define it.
Soil and Water Assessment Tool
The Soil and Water Assessment Tool, or SWAT, is a public-domain watershed model that predicts how management decisions affect water, sediment, nutrient, and pesticide yields.
Sokoto (landform)
Sokoto (landform): the Sokoto River, a left-bank tributary of the Niger in semi-arid northwestern Nigeria, and the Sokoto Plains; 193,000 km2 Sokoto-Rima basin, 700 to 900 mm rain, Bakolori and Goronyo dams, shrinking floodplain.
Somme (river)
The Somme is a 245 km river in northern France, rising at Fonsomme (Aisne) and flowing west to the Baie de Somme estuary; chalk-aquifer-fed, canalized as the 156 km Canal de la Somme, site of the 2001 groundwater flood.
Son
The Son (सोन), also written Sone, is a major ephemeral right-bank tributary of the Ganges in India, rising near Amarkantak and joining it near Patna.
Song Hong
Song Hong (Sông Hồng, Red River), FEOW freshwater ecoregion 761, covers the whole Red River basin in Vietnam, China, and Laos, draining to the Gulf of Tonkin, with 16 endemic fish species and a heavily dammed, sediment-starved delta.
Songhua Jiang
Songhua Jiang (松花江), the Songhua River, is China's third largest river by discharge and the Amur's largest tributary, draining a 556,800 km² basin in northeast China with the Nenjiang and Second Songhua as sources.
Souris
Souris River (riviere Souris), called Mouse River in the United States: a 700 km Saskatchewan-North Dakota-Manitoba tributary of the Assiniboine River, governed by the 1989 Canada-US water supply and flood control agreement.
South America Caribbean Drainages - Trinidad
South America Caribbean Drainages - Trinidad is FEOW freshwater ecoregion 304, a Neotropic tropical and subtropical coastal rivers unit covering Caribbean-draining rivers of northern South America plus Trinidad, with South American-derived fish fauna.
South Platte
The South Platte River is a major tributary of the Platte River that rises in the Colorado Rockies, flows through Denver, and joins the North Platte in Nebraska.
South Saskatchewan
South Saskatchewan River, formed by the Bow and Oldman rivers in Alberta, flows through Lake Diefenbaker and past Saskatoon to join the North Saskatchewan; its basin covers 172,900 km2 and supplies most of Saskatchewan's drinking water.
Southeast Adriatic Drainages
Southeast Adriatic Drainages (FEOW ecoregion 420) is a Palearctic temperate coastal rivers ecoregion covering Albanian and western Balkan drainages from the Drin to the Vjosa, rich in endemic fish and eutrophying the southeastern Adriatic coast.
Southeastern Korean Peninsula
Southeastern Korean Peninsula (FEOW ecoregion 639): temperate coastal-river freshwater ecoregion covering rivers draining to Korea's southern and southeastern coasts, plus Ulluengdo, Jejudo, and Tsushima, with 11 endemic fish species.
Southeastern Mata Atlantica
Southeastern Mata Atlantica is a freshwater ecoregion in southern Brazil covering coastal rivers and lagoons between the Rio Araranguá and the Rio Ribeira de Iguape.
Southern Bug
Southern Bug (Південний Буг), 806 km river entirely within Ukraine, flowing from the Volyn-Podilska Highlands to the Dnipro-Buzky Firth; third-longest such river, historically Hypanis, heavily regulated, and since 2022 Mykolaiv's proposed drinking-water source.
Southern Central Sumatra
Southern Central Sumatra (FEOW ecoregion 738) is an Indonesian freshwater ecoregion of tropical coastal rivers draining to the Strait of Malacca, including the Rokan, Siak, Kampar, Indragiri, and Batang Hari rivers, with about 20 endemic fish species and the highest functional richness (154 FEs) among Sundaland's 13 freshwater ecoregions.
Southern Eastern Rift
Southern Eastern Rift, FEOW ecoregion 566, a freshwater ecoregion of the Gregory Rift Valley in Kenya and Tanzania; xeric, endorheic basins with soda lakes (Natron, Magadi, Nakuru), endemic Oreochromis fish, and over a million flamingos and wetland birds at key sites.
Southern Gulf of Guinea Drainages
Southern Gulf of Guinea Drainages is a freshwater ecoregion, number 533 in the FEOW framework, covering short coastal rivers in Cameroon, Congo, Equatorial Guinea, and Gabon known for endemic fishes.
Southern Hudson Bay
Southern Hudson Bay (FEOW ecoregion 110) is a Canadian freshwater ecoregion of temperate coastal rivers draining northeastern Manitoba, northern Ontario, and western Quebec into Hudson and James bays, with depauperate, non-endemic fish fauna.
Southern Iberia
Southern Iberia is a freshwater ecoregion, number 413 in the Freshwater Ecoregions of the World framework, covering Spain's far south from the Guadiana to the Segura rivers.
Southern Upper Guinea
Southern Upper Guinea (FEOW ecoregion 512) is a West African freshwater ecoregion covering nearly all of Liberia, southern Guinea, and western Côte d'Ivoire, defined by the short Mano, Lofa, St. Paul, St. John, Cestos, and Cavally river basins with about one-fifth of 151 fish species endemic.
Spokane River
The Spokane River is a 111-mile tributary of the Columbia River that runs from Lake Coeur d'Alene in Idaho through Spokane, Washington, to Lake Roosevelt.
Spuyten Duyvil Creek
Spuyten Duyvil Creek was a tidal waterway in New York City connecting the Hudson and Harlem rivers around northern Manhattan, replaced by the Harlem River Ship Canal.