River Mouth: Where Flowing Water Meets a Larger Body

The mouth of a river is the terminus where it discharges into a larger body of water—an ocean, sea, lake, reservoir, or another river. It is the endpoint of the river's course, contrasting with the source (headwaters).

Key Characteristics

• Sediment Deposition: Velocity drops → sediment load settles → forms deltas (e.g., Nile, Mississippi, Mekong) or alluvial fans (in lakes).
• Estuaries: Where freshwater mixes with tidal saltwater—brackish, nutrient-rich, biologically productive (nurseries for fish, birds).
• Dynamic Morphology: Mouths migrate, silt up, or shift due to tides, currents, storms, and human engineering (jetties, dredging).
• Ecological & Human Hub: Ports, cities, fisheries, and wetlands cluster at river mouths (Shanghai, Rotterdam, New Orleans, Kolkata).

Not "Just the End"

The mouth is a transition zone—hydrologically, ecologically, and economically. It connects the watershed's accumulated water, nutrients, pollutants, and sediments to the global ocean system.