River delta slope offshore, waves will make river deltas smoother. Waves can also be responsible for carrying sediments away from the river delta, causing the delta to retreat. For deltas that form further upriver in an estuary, there are complex yet quantifiable linkages between winds, tides, river discharge, and delta water levels. Erosion is also an important control in tide-dominated deltas, such as the Ganges Delta, which may be mainly submarine, with prominent sandbars and ridges. This tends to produce a "dendritic" structure. Tidal deltas behave differently from a river- and wave-dominated deltas, which tend to have a few main distributaries. Once
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