Allendeltas

Allendeltas is a term sometimes used to refer to river deltas that are formed by rivers flowing into a large body of water, such as an ocean, sea, or lake, where the river's flow is influenced by tidal forces. These deltas are characterized by a network of distributary channels that carry sediment and water away from the main river channel. The morphology of allendeltas is a result of the interplay between riverine processes, such as deposition of sediment, and marine processes, such as tidal currents, wave action, and sea-level fluctuations.

These deltas often exhibit a characteristic fan shape, with sediment being deposited as the river's velocity decreases upon entering the larger body of water. Tidal influence can lead to the formation of tidal channels that can rework and redistribute the deposited sediments, creating complex patterns of sandbars, mudflats, and marshlands. The presence of tides can also affect the salinity of the deltaic environment, leading to the development of brackish or saline ecosystems.

Allendeltas are important for a variety of ecological and economic reasons. They are often highly productive ecosystems, supporting diverse plant and animal life. They also serve as important areas for human activities, including agriculture, fishing, and transportation. However, allendeltas are also vulnerable to environmental changes, such as sea-level rise, increased storm frequency, and human development, which can impact their stability and ecological integrity.