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
Danube Delta Danube Delta The Danube Delta ( ; , , ) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. The greater part of the Danube Delta lies in Romania (Tulcea County). Its approximate surface area is , of which is in Romania. With the lagoons of Razim–Sinoe ( with water surface), located south of the main delta, the total area of the Danube Delta is . The Razim–Sinoe lagoon complex is geologically and ecologically related to the delta proper and the combined territory is listed as a World Heritage