What are 'headwaters' in relation to rivers?

Headwaters refer specifically to the source area or beginning of a river. This is where the river originates, often found in highland or mountainous regions where rainfall or melting snow contributes to the initial flow of water. The characteristics of headwaters typically include faster flow rates due to the steep gradients, increased turbulence, and lower temperatures compared to lower parts of the river.

Understanding headwaters is vital for grasping how rivers develop and change as they flow downstream. This region is crucial for the entire river system, influencing water quality, ecosystems, and sediment transport. The other options describe different aspects of river systems, such as confluences with lakes, flood-prone areas, or river bends, but do not accurately define what headwaters are.