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
Yukon–Kuskokwim Delta Yukon–Kuskokwim Delta The Yukon–Kuskokwim Delta is a river delta located where the Yukon and Kuskokwim rivers empty into the Bering Sea on the west coast of the U.S. state of Alaska. At approximately in size, it is one of the largest deltas in the world. It is larger than the Mississippi River Delta (which varies between ), and comparable in size to the entire U.S. state of Louisiana (). The delta, which consists mostly of tundra, is protected as part of the Yukon Delta National Wildlife Refuge. The delta has approximately 25,000 residents. 85% of these are Alaska Natives: Yupik