River delta The Okavango Delta in Botswana is one example. The generic term "mega delta" can be used to describe very large Asian river deltas, such as the Yangtze, Pearl, Red, Mekong, Irrawaddy, Ganges-Brahmaputra, and Indus. The formation of a delta is complicated, multiple, and cross-cutting over time, but in a simple delta three main types of bedding may be distinguished: the bottomset beds, foreset/frontset beds, and topset beds. This three part structure may be seen in small scale by crossbedding. The Ganges/Brahmaputra combination delta, which spans most of Bangladesh and empties into the Bay of Bengal, is the world's largest delta.
River delta is called an inverted river delta. Sometimes a river divides into multiple branches in an inland area, only to rejoin and continue to the sea. Such an area is called an "inland delta", and often occurs on former lake beds. The Inner Niger Delta and Peace–Athabasca Delta are notable examples. The Amazon also has an inland delta before the island of Marajó, and the Danube has one in the valley on the Slovak-Hungarian border between Bratislava and Iža. In some cases, a river flowing into a flat arid area splits into channels that evaporate as it progresses into the desert.