River deltas are classified by the dominant depositional/reworking process controlling their morphology: wave-dominated deltas (smooth, arcuate coastlines reworked by strong wave action, e.g., Nile), river-dominated (fluvial-dominated) deltas (birds-foot/lobate shapes with distributary-mouth-bar deposition dominating over marine reworking, e.g., Mississippi), and tide-dominated deltas (funnel-shaped, elongated tidal sand ridges/channels, e.g., Ganga-Brahmaputra).