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.
Lena Delta Wildlife Reserve Lena Delta Wildlife Reserve Lena Delta Nature Reserve () is a "Zapovednik" (“scientific nature reserve”) located in the delta of the Lena River in Sakha Republic, in the far north of eastern Siberia, Russia. The reserve is divided into two subareas, and has a total land area of , making it one of the largest protected areas in Russia. The delta itself has a size of about , making it one of the largest in the world. It protects large concentrations of birds, including swans, geese and ducks, loons, shorebirds, raptors and gulls. It is also an important fish spawning