Large River Deltas

Deltas are essential for studying the nature and behaviour of a large river. They are part subaerial and part subaqueous accumulation of sediment at the mouth of a river draining into a sea or a lake. A delta is divided primarily into a subaerial delta and a subaqueous delta. The subaerial delta may be further divided into a tidal delta and a non-tidal delta. Morphologically deltas can be divided into three parts: delta plain, delta front, and prodelta. Deltas of large rivers can be complex. Such a delta may extend over a large area and display varied morphology, multiple delta-forming processes, and the contribution of water and sediment discharges of the large river. The Ganga-Brahmaputra Delta demonstrates the complex nature of major deltas. The evolution of the delta is related to changes in the river system, climate, and sea level during the Late Pleistocene and Holocene.