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
Mississippi River Delta U.S. The coastal area is the nation's largest drainage basin and drains about 41% of the contiguous United States into the Gulf of Mexico at an average rate of 470,000 cubic feet per second. The modern Mississippi River Delta formed over the last approximately 7,000 years as the Mississippi River deposited sand, clay and silt along its banks and in adjacent basins. The Mississippi River Delta is a river-dominated delta system, influenced by the largest river in North America. The shape of the current birdfoot delta reflects the dominance the river exudes over the other hydrologic and geologic processes at