Where is a delta landform

The majority fall into one of the following five categories:. Strong tidal currents and high wave energy , which tend to disperse sediment, inhibit delta formation.

A number of factors control the shape of large deltas, many of which have persisted over long periods of time. For example, the inflowing water may move below the surface, down the slope at the front of the delta; spread out over the surface of the standing body of water; or mix with it.

Large deltas, such as that of the Saskatchewan River , consist of a vast network of distributary channels. As these deltas develop, so, too, does a low-lying delta plain that features different sedimentary environments such as levees, backswamps and marshes see Wetlands.

Underground reserves of oil and gas can form with the layering of sedimentary environments over time, as seen in the Mackenzie River delta region in the Northwest Territories. The project has been debated since the s and has attracted support as well as opposition from First Nations in the region. This international agreement sets out a framework for protecting wetland ecosystems. Industrial development on the delta, such as the proposed Terminal 2 shipping facility at Roberts Bank in Delta , BC, are controversial due to the importance of the Fraser River delta as a stopover for migratory birds.

Flood control is also a challenge in delta lowlands. In the case of the Fraser River delta, for example, researchers anticipate the need for greater investment in flood protection measures as sea levels rise due to climate change. See also River Landform. Kevin P. Arthur C. Benke and Colbert E. Cushing, eds. Delta landforms occur where rivers dump loads of sediment — silt, sand and small rocks — at their mouths in oceans or large lakes.

Their brackish, nutrient-rich waters and rich soils have long made deltas such as these important fishing grounds, farmland and settlement sites for human beings. Civilization has thrived in the Nile delta, which historically provided fertile farmland, since B. The Mississippi delta began forming about 5, years ago and continues to evolve in shape, having advanced the Louisiana coastline here some 15 to 50 miles into the Gulf.

In recent decades, however, land subsidence, sea-level rise, human impacts on flow and sediment load and occasional hurricanes have resulted in significant rates of land loss in the Mississippi delta, which includes hundreds of thousands of acres of valuable wetlands.

The Yellow River Huang He of China carries the heaviest sediment load, making its delta one of the richest in the world. This river carries millions of tons of silt each year. These impacts as well as climate effects have greatly reduced the amount of water and sediment carried by the Huang He, which threatens wetlands, aquaculture and human livelihood. More than 40, square miles in area, the delta formed by the many mouths of the Ganges and Brahmaputra rivers at the Bay of Bengal ranks as the largest in the world as well as one of the most fertile and — with better than million inhabitants — one of the most heavily populated.

The ecosystem what was once the world's largest desert estuary has been reduced to a fraction of its former area, and many indigenous species are vulnerable, threatened, or endangered. Finally, decades of river management prevent the Mississippi River from naturally flowing through its delta wetlands. Like the Nile delta, the Mississippi delta is also eroding. This situation contributed to the devastation caused by Hurricane Katrina in Delta Blues Delta blues is a style of music developed by African-American artists living and performing in the Mississippi Delta region of the southern United States.

The Mississippi Delta is actually a flood plain between two rivers in northwestern Mississippi, the Mississippi and the Yazoo, it is sometimes to as the Yazoo-Mississippi Delta. Slide guitar is one of the standard instruments used by delta blues musicians, while familiar topics include poverty and injustice. Robert Johnson, widely recognized as one of the greatest guitarists of all time, played the Delta blues. Listen to Robert Johnson here. Also called an alpha predator or top predator.

Also called a birdfoot delta or bird's-foot delta. Usually rivers enter another body of water at their mouths. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited. Jeannie Evers, Emdash Editing. Caryl-Sue, National Geographic Society.

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Text on this page is printable and can be used according to our Terms of Service. Any interactives on this page can only be played while you are visiting our website. You cannot download interactives. Search through these resources to discover more about unique landforms and landscapes around the world. Landforms are natural and distinctive features. Explore how they show up in various landscapes. These resources can be used to teach middle schoolers more about the natural world, its distinctive features, and landscapes.

Of that, only about 1. Most of our drinking water comes from rivers and streams. This water is the lifeline of ecosystems around the world. Freshwater is a precious resource on the Earth's surface. It is also home to many diverse fish, plant, and crustacean species. The habitats that freshwater ecosystems provide consist of lakes, rivers, ponds, wetlands, streams, and springs. Use these classroom resources to help students explore and learn about these places.

A biome is an area classified according to the species that live in that location. Temperature range, soil type, and the amount of light and water are unique to a particular place and form the niches for specific species allowing scientists to define the biome. However, scientists disagree on how many biomes exist. Some count six forest, grassland, freshwater, marine, desert, and tundra , others eight separating two types of forests and adding tropical savannah , and still others are more specific and count as many as 11 biomes.

Use these resources to teach middle school students about biomes around the world. A habitat is an environment where an organism lives throughout the year or for shorter periods of time to find a mate. The habitat contains all an animal needs to survive such as food and shelter.

A microhabitat is a small area which differs somehow from the surrounding habitat. Its unique conditions may be home to unique species that may not be found in the larger region. Unfortunately, some habitats are threatened by pollution, extreme weather, or deforestation. This puts many of the species that live there in danger and is causing many populations to decline.

Explore different types of habitats and microhabitats with this curated collection of classroom resources. Use this map to help students learn more about the Okavango Delta in Africa, including how it was formed and why it is important to the people and wildlife of southwestern Africa. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary.

Types of Deltas There are two major ways of classifying deltas. Influence There are four main types of deltas classified by the processes that control the build-up of silt: wave -dominated, tide -dominated, Gilbert deltas, and estuarine deltas.

Deltas and People Deltas are incredibly important to the human geography of a region. Disappearing Deltas Extensive river management threatens deltas. The triangle-shaped Nile Delta is a perfect example of an arcuate delta.