River

A river transparent png download is a ribbon-shaped stream of water that flows downward due to gravity’s influence. A river might be vast and deep, or it can be shallow enough to wade across. A stream, creek, or brook is a flowing body of water that is smaller than a river. Some rivers run all year, while others flow just during certain seasons or after particularly heavy rain. Thousands of miles of river can be found in the world’s major rivers. Rivers’ erosional force can create geologic marvels like the Grand Canyon.

Every river has a point where the water begins to flow. A headwater is the name for this type of source. Rainfall or snowmelt in the mountains can provide the headwater, but it can also come from groundwater or form at the edge of a lake or large pond. The mouth of a river is where the water flows into a bigger body of water, such as a lake or the ocean. Rivers may pass through wetlands along the course, where plants slow the flow and filter pollutants.

The water that flows through rivers is fresh, meaning it contains less than 1% salt. Rivers, on the other hand, continue to transport and distribute vital minerals and nutrients that support plant and animal life. As a result, some of the world’s most biodiverse environments can be found near rivers. Scientists estimate that each year, all of the world’s rivers transport around 3.6 billion metric tons (four billion tons) of salt from land to sea.

Rivers can also generate an estuary, which is formed when salty seawater meets with freshwater near the river mouth to create “brackish water.” The Hudson River in New York, USA, is an example of an estuary with brackish water flowing upstream for more than 241 kilometers (150 miles).

Pebbles, sand, and silt are carried by fast-flowing rivers. These sediments sink and stack up to form deltas as the river slows down—as in a marsh, on the outside of a curve, or where the river widens, such as at the mouth. Rivers that overflow their banks deposit silt in the flood plain surrounding them. These deltas and floodplains are extremely fruitful agricultural zones that are quite valuable to the people who live nearby.

The Nile River and its delta, for example, aided in the formation of the Egyptian empire that built the pyramids. Farmers in California’s Central Valley flood zone now produce almost one-third of all vegetables and two-thirds of all fruits and nuts consumed in the United States.

Humans use rivers for irrigation, drinking water, transportation, electricity generation via hydroelectric dams, and recreational activities such as swimming and boating. Each of these users has the potential to negatively impact the health of a river and its ecosystems. Scientists known as limnologists are responsible for monitoring the health of rivers, lakes, and streams.