Watersheds and River Basins

Hydrosphere The hydrosphere is the total amount of water on Earth. The hydrosphere includes water that is on the surface, underground, and in the air. The hydrosphere can be liquid, vapor, or ice. On Earth, liquid water exists on the surface in the form of oceans, lakes and rivers.

Watershed A watershed is a bowl-like landform defined by highpoints and ridgelines that descend into lower elevations and stream valleys.

Watershed A watershed carries water "shed" from the land after rain falls and snow melts. Drop by drop, water is channeled into soils, groundwaters, creeks, and streams, making its way to larger rivers and eventually the sea.

Watershed Water is a universal solvent, affected by all that it comes in contact with: the land it traverses, and the soils through which it travels. The important thing about watersheds is: what we do on the land affects water quality for all communities living downstream.

Watershed Divide  A watershed starts at the highest points on the landscape, like mountain peaks and ridgelines that divide one valley or drainage from another. The imaginary line that connects those high points is called the watershed divide.

Watershed Divide Precipitation that falls inside the watershed divide will flow down to the water body (like a river or lake) at the lowest point in that landscape. The watershed is usually named after that water body.

Headwaters Headwaters are not the highest elevational point in a watershed; they are fed by runoff, springs, or snow melt that originates further upslope!

Runoff Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called overland flow. A land area which produces runoff draining to a common point is called a watershed.

Drainage Basin A drainage basin or catchment basin is an extent or an area of land where all surface water from rain, melting snow, or ice converges to a single point at a lower elevation, usually the exit of the basin, where the waters join another body of water, such as a river, lake, reservoir, estuary, wetland, sea, or ocean.

River Basins A river basin is the land that water flows across or under on its way to a river. Just as a bathtub catches all of the water that falls within its sides, a river basin sends all of the water falling within it to a central river and out to an estuary or to the ocean.

River Basins The Yadkin–Pee Dee River Basin is a large river basin in the eastern United States, covering around 7,221 square miles, making it the second largest in the state of North Carolina.

Confluence The point where a tributary joins a larger river, called the main stem, or where two streams meet to become the source of a river of a new name, such as the confluence of the South Yadkin River and Yadkin River in North Carolina.

Tributaries A tributary is a freshwater stream that feeds into a larger stream or river. The point where a tributary meets the main river is called the confluence. Tributaries, also called affluents, do not flow directly into the ocean.

Tributaries Most large rivers are formed from many tributaries. Each tributary drains a different watershed, carrying runoff and snowmelt from that area. Each tributary's watershed makes up the larger watershed of the main river. Can you name 3 tributaries to the Yadkin River?

Floodplain A flood plain (or floodplain) is a generally flat area of land next to a river or stream. It stretches from the banks of the river to the outer edges of the valley.

Mouth of River The place where a river enters a lake, larger river, or the ocean is called its mouth. River mouths are places of much activity.

Reservoir A reservoir is an enlarged natural or artificial lake, storage pond or impoundment created using a dam or lock to store water. Reservoirs can be created by controlling a stream that drains an existing body of water.