GEOLOGY

Detailed explanation-1: -Precipitation and groundwater add to the river’s flow. It is also fed by other streams, called tributaries. For instance, the Amazon River receives water from more than 1, 000 tributaries. Together, a river and its tributaries make up a river system.

Detailed explanation-2: -A tributary is a freshwater stream that feeds into a larger stream or river. The larger, or parent, river is called the mainstem. The point where a tributary meets the mainstem is called the confluence. Tributaries, also called affluents, do not flow directly into the ocean.

Detailed explanation-3: -Water from some source like a spring, snow melt, or a lake starts at this high point and begins to flow down to lower points. As the water flows down, it may pick up more water from other small streams, springs or or from rain or snow melt. These streams may slowly join together to form a larger stream or river.

Detailed explanation-4: -A confluence occurs when two or more flowing bodies of water join together to form a single channel. Confluences occur where a tributary joins a larger river, where two rivers join to create a third or, where two separated channels of a river, having formed an island, rejoin downstream.

Detailed explanation-5: -A river system is a network of a source, tributaries, flood plains, and wetlands in relation to the main river. These components make up the river’s watershed.