4 min readImage of the Day for August 28, 2026The meandering Congaree River sustains towering forest ecosystems and fashions oxbow lakes as it shifts across its floodplain. NASA Earth ObservatoryAug 28, 2026 Article
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Among the 63 U.S. national parks, few are as defined by a single river's floodplain as Congaree National Park in South Carolina. While the features are also prominent in other parks, a full 80 percent of Congaree National Park lies within the Congaree River floodplain.
It's a place home to one of the largest intact tracts of old-growth bottomland hardwood forests in the United States. In this image captured by the OLI (Operational Land Imager) on Landsat 9, the river winds through the forested plain, along with curving bands of green that trace old channels, ridges, and swales left behind as the river gradually migrated across it. Slight differences in elevation in these paleochannels and other landforms affect how frequently they flood, producing distinct ecosystems that appear in contrasting shades of green.
The river flows through flat, soft terrain, which encourages the formation of bends and meanders. Water typically flows faster on the outside of bends, leading to more rapid erosion as the channel carves into the outer riverbank. It moves more slowly on the inside of bends, resulting in the deposition of sediment and the growth of sandy features called point bars. Over time, this process can cut off a bend from the main river channel, forming U-shaped oxbow lakes.
