Why do rivers get wider

For example, deforestation and urbanization lead to the excavation of sand and stones for building along riverbeds. These types of land reform ultimately result in the widening of a river. Water upstream may be composed of snow and ice. However, downstream the climate may change and become gradually warmer, causing snow and ice to melt. This melting increases the flow of a river, which increases its width. Near the source, general river geomorphology is categorized as a straight channel.

However, downstream the water flow meanders due to the erosion of outer parts of bends in the river. The river becomes wider as the meandering channel is eroded and washes away more materials along the riverbank.

The cross-sectional area of the river, therefore, becomes larger. The size and shape of a river changes as flows downstream. Molly John July 30 in Environment.

Puma, Cougar, Or Mountain Lion? Bhopal Gas Tragedy. Greenland Shark. Sharks Are Fascinating, Not Fearsome. Right from its youth days to old age, a river has a single aim to connect with the ocean.

There is a place where a stream or a river meets the ocean. The estuary is where the freshwater connects with the saltwater. The estuary is also called bay, slough, lagoon, or sound. In an estuary, you can see water circulating in and out. When the freshwater meets the ocean, it turns blackish and salty.

There are many beautiful estuaries in the world where you can witness the enchanting amalgamation of the river and the ocean. When the mouth of the river creates the flow of freshwater, the tides are responsible for making the largest flow of the ocean water. When seawater flows into the estuary, the estuarine current is developed.

As saltwater is heavier, the estuarine current will sink and move to the bottom. The less-dense freshwater creates an anti-estuarine current when it enters the estuary.

Near the surface regions, these anti-estuarine currents are the strongest. There are different types of estuaries in the world that are segregated into different categories. There are 4 major categories that include coastal plain, tectonic, fjord, and bar-built estuaries. You can also find some freshwater estuaries as well which are formed when a river falls into the lake. These freshwater estuaries then travel to the ocean for further mix.

Just like the ocean ecosystem, there is an estuary ecosystem as well. These environments provide a safer and healthy environment for shellfishes, small fishes, migrating birds, and some shore animals. The water in estuaries is highly rich in minerals and nutrients like bacteria and plankton that sustain a diverse ecosystem.

For instance, the decomposing of plant matter makes a healthy food source for many species. Not only for animals, but estuaries can also become a great community for humans. The freshwater is hygienic for drinking; also, the access to both ocean and river can pave the way for development. Not only rivers and oceans meet, but two rivers also meet and then travel to the ocean together. The merger of two rivers is called confluence. It is the process that defines the amalgamation of two flowing bodies.

In confluence, two rivers will join to form a single channel that travels to the ocean. Even two tributaries can meet confluence depending on the intensity. A confluence may occur in various configurations. Tyson Brown, National Geographic Society. National Geographic Society. For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher.

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Floods are events where water overflows onto land that is typically dry. This can occur when there is a large amount of rain, rapid snow or ice melt, a blast of water onto a coastline during a storm, or the failure of manmade infrastructures, such as dams or levees.

Floods are among the most expensive and frequent natural disasters in the United States, and as the impacts of climate change are more acutely felt, floods are expected to worsen. In addition to property damage, floods, on average, kill more people than tornadoes, hurricanes, or lightning strikes in the United States each year.

Learn more about floods with these resources. A river is a large, natural stream of flowing water. Rivers are found on every continent and on nearly every kind of land. The surrounding river basin has a population of more than four hundred million people. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content.