What process changes a delta?
An abandoned delta forms as a river develops a new channel, leaving the other to dry up or stagnate. This process is called avulsion. Avulsion occurs when the slope of a channel decreases and the sediment build-up increases. The process of avulsion in deltaic lobes is called delta lobe switching.
What causes deltas to change over time?
One of the most important perceptions needed to understand deltas is how their depositional framework changes with time. This occurs because the channel gradient and transporting power of a delta river decreases as the deltaic lobe extends farther seaward and shorter routes to the ocean become available.
What is a tide dominated delta?
Tide-dominated deltas are comprised of a river that is directly connected to the sea via channels that are typically flanked by low-lying vegetated floodplains and swamp areas.
What is wave dominated delta?
Wave-dominated deltas, such as the Nile Delta or the St. George lobe of the Danube Delta, are deltas where waves are the dominant factor shaping the fluvial sediment . Compared to tidal and river-dominated deltas, wave dominated deltas often have smooth coastlines, and few (~1) distributary channels (Fig.
What is a wave dominated coast?
Price (1955) used the term wave-dominated coasts to describe the morphology of depositional shores where consistent, relatively large waves, with their associated strong wave-generated currents, have produced a smoothed shore of sandy sediments.
What is the definition for deltas?
del·ta | \ ˈdel-tə \ Essential Meaning of delta. 1 : the fourth letter of the Greek alphabet. 2 : a piece of land shaped like a triangle that is formed when a river splits into smaller rivers before it flows into an ocean a river delta the Ganges/Nile Delta.
How do deltas occur?
A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment.
What is a wave dominated delta?
What does a wave dominated coast look like?
Most authors consider long, smooth, barrier coasts with few inlets and poorly developed ebb deltas as “wave-dominated”. Conversely, mesotidal coasts tend to develop short, drumstick-shaped barriers with well-developed ebb deltas. They are considered as tide-dominated barriers.
Tide Dominated Deltas. The shape of a delta is influenced by sediment input, wave energy, and tidal energy. Deltas which undergo strong tidal interaction are classified as tide-dominated deltas. As sediment travels out of the delta into the sea, high tides and flood tides confine sediment on the delta plain and low tides carry sediment seaward.
What are the landforms of Delta?
Delta Plains. Delta land forms are divided into upper and lower plains. An upper delta plain consists of lagoons, bogs, floodplains and braided stream channels. Lacustrine wetlands and marshes are also commonly formed in upper deltas.
What is the Delta landform?
A delta landform is a sophisticated depositional feature that typically occurs at the mouth of a river. By definition, the mouth of the river is where the river drains into a water body such as lake, ocean or sea, leading to reduction of the rivers capability to transport sediment any farther.
What is an example of a Delta?
An example of such a delta is the one formed by the Sacramento-San Joaquin River in northern California. An inland delta is rare. It refers to a delta that empties into a plain. The Okavango Delta in Botswana is a classic example of this type of delta.