The River

Natural flowing watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river A river could flow into the ground and dry up completely at the end of its course, without reaching another body of water Small rivers may be called by several other names: stream, creek, brook, rivulet, and rill

Rivers are part of the hydrological cycle Water generally collects in a river from precipitation through a drainage basin from surface runoff Other sources include groundwater recharge, springs, and the release of stored water in natural ice and snow packs (e.g. from glaciers) Potamology is the scientific study of rivers while limnology is the study of inland waters in general

Spring

Where do rivers begin? A river begins at a source (often several sources) and ends at a mouth Follow a path called a course. The water usually confined to a channel, made up of a stream bed between banks Larger rivers have a wider floodplain shaped by flood-waters over-topping the channel Floodplains may be very wide in relation to the size of the river channel.

Rivers can flow down mountains, through valleys (depressions) or along plains Can create canyons or gorges

Merced River, Yosemite NP

Columbia River, WA.

River Flow Upriver (or upstream) refers to the direction towards the source of the river, (against the direction of flow) Downriver (or downstream) describes the direction towards the mouth of the river, in which the current flows

A river system is made up of a main river and all its tributaries The point where two rivers join is called a confluence Example, confluence of Mississippi and Ohio, is near Cairo, Illinois. The entire land area drained by a river system is called a river basin, or a watershed

Valleys are elongated depressions, carved out over a period of thousands of years, through which rivers run Become wider and flatter toward the mouth Canyons Gorges are deep and steep sided valleys formed by young rivers cutting mainly downward through the land One of the largest is the Grand Canyon of the Colorado River

In a canyon river, where the river bed drops quickly, swift and churning waters, called rapids, are produced Waterfalls, the sudden falling of water from high ledges, occur frequently on many rivers in mountainous regions

Grand Canyon, Arizona Colorado River

Upper Falls, Yellowstone NP

Floodplains are broad, flat landforms built up by the sediments of successive floods. Natural levees, which are the highest portion of the plain Meanders, or large winding loops in a river's course, are common on floodplains Oxbow lakes are remnants of old meanders cut off from the river by a change of course

Meander

Oxbow Lake

Deltas are large landforms, usually triangle- shaped, Formed by sediment carried by rivers entering the shallow water of the sea The ocean backs up into the river's mouth to form estuaries. These V-shaped bays are often excellent harbors, example: Hudson River delta

Mississippi Delta

Estuaries A partly enclosed coastal body of brackish water with one or more rivers or streams flowing into it Has a free connection to the open sea

Matagorda Bay

Drainage Basin An area of land where surface water from rain, melting snow converges to a single point at a lower elevation,

Texas Drainage Basins Texas has 23 major watersheds Managing these systems is difficult due to limited rainfall Some of these drainage basins are in karst regions (water is stored underground)

River Profile