Portal:Rivers

From Wikipedia, the free encyclopedia
PortalWikiProject RiversTalk page
The Rivers Portal

Introduction

Elwha River in the Olympic Peninsula

A river is a natural flowing watercourse, usually a freshwater stream, flowing on the Earth's land surface or inside caves towards another waterbody at a lower elevation, such as an ocean, sea, bay, lake, wetland, or another river. In some cases, a river flows into the ground or becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to by names such as creek, brook, and rivulet. There are no official definitions for these various generic terms for a watercourse as applied to geographic features, although in some countries or communities, a stream is customarily referred to by one of these names as determined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and Northeast England, and "beck" in Northern England. Sometimes a river is defined as being larger than a creek, but not always; in English the language is vague compared to some langauges like French, where a fleuve flows into the sea and a rivière is a tributary of another rivière or fleuve.

Rivers are an important part of the water cycle. Water from a drainage basin generally collects into a river through surface runoff from precipitation, meltwater released from natural ice and snowpacks, and other underground sources such as groundwater recharge and springs. Rivers are often considered major features within a landscape; however, they actually only cover around 0.1% of the land on Earth. Rivers are also an important natural terraformer, as the erosive action of running water carves out rills, gullies, and valleys in the surface as well as transferring silt and dissolved minerals downstream, forming river deltas and islands where the flow slows down. As a waterbody, rivers also serve crucial ecological functions by providing and feeding freshwater habitats for aquatic and semiaquatic fauna and flora, especially for migratory fish species, as well as enabling terrestrial ecosystems to thrive in the riparian zones.

Rivers are significant to humankind since many human settlements and civilizations are built around sizeable rivers and streams. Most of the major cities of the world are situated on the banks of rivers, as they are (or were) depended upon as a vital source of drinking water, for food supply via fishing and agricultural irrigation, for shipping, as natural borders and/or defensive terrains, as a source of hydropower to drive machinery or generate electricity, for bathing, and as a means of disposing of waste. In the pre-industrial era, larger rivers were a major obstacle to the movement of people, goods, and armies across regions. Towns often developed at the few locations suitable for fording, building bridges, or supporting ports; many major cities, such as London, are located at the narrowest and most reliable sites at which a river could be crossed via bridges or ferries. (Full article...)

Map depicting the Gulf Coast of Texas, with coastal counties labeled and estuaries color-coded
Map of the major and minor estuaries of the Gulf Coast of Texas

The U.S. state of Texas has a series of estuaries along its coast on the Gulf of Mexico, most of them bounded by the Texas barrier islands. Estuaries are coastal bodies of water in which freshwater from rivers mixes with saltwater from the sea. Twenty-one drainage basins terminate along the Texas coastline, forming a chain of seven major and five minor estuaries: listed from southwest to northeast, these are the Rio Grande Estuary, Laguna Madre, the Nueces Estuary (Corpus Christi Bay), the MissionAransas Estuary (Aransas Bay), the Guadalupe Estuary (San Antonio Bay), the ColoradoLavaca Estuary (Matagorda Bay), East Matagorda Bay, the San Bernard River and Cedar Lakes Estuary, the Brazos River Estuary, Christmas Bay, the TrinitySan Jacinto Estuary (Galveston Bay), and the SabineNeches Estuary (Sabine Lake). Each estuary is named for its one or two chief contributing rivers, excepting Laguna Madre, East Matagorda Bay, and Christmas Bay, which have no major river sources. The estuaries are also sometimes referred to by the names of their respective primary or central water bodies, though each also includes smaller secondary bays, inlets, or other marginal water bodies.

These water bodies include some of the largest and most ecologically productive coastal estuaries in the United States and contribute significantly to the ecological and economic resources of Texas. They are included in a number of national protected areas such as National Wildlife Refuges, a National Seashore, and a National Estuarine Research Reserve, as well as various state parks and other regional protected areas. The two most economically important (the Nueces and Trinity–San Jacinto Estuaries) have been designated by the United States Environmental Protection Agency as estuaries of national significance under the National Estuary Program. The Gulf Intracoastal Waterway runs through each of the major estuaries, linking Texas ports with others along the Gulf Coast of the United States. (Full article...)
List of selected articles

Selected Quote

A river is more than an amenity, it is a treasure.
Oliver Wendell Holmes Jr., Speaking About the Delaware River, 1931

Selected picture

Photograph: Ansel Adams

The Tetons and the Snake River (1942)

General images - show new batch

The following are images from various river-related articles on Wikipedia.

Did you know?

Maksimovsky rock in the Chusovaya River in Russia

Related portals

Selected Panorama

Topics

Subcategories

Category puzzle
Category puzzle
Select [►] to view subcategories

Quality content

Featured articles

Featured lists

Good articles

Things to do

Tasks clipboard
Tasks clipboard

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

More portals