Watershed — Science definition
Defined in 2 courses:
- An area whose drainage connects toward a common outlet under a defined landscape model. (Science 6: Matter, Energy & Earth Systems)
- The entire area of land where all the water that falls on it drains to a common outlet, such as a river, lake, or bay. (Physics & Environmental Science)
Where it is taught
- Watersheds, Water Quality & Sampling Limits — Ecosystems, Watersheds & Conservation, Science 6: Matter, Energy & Earth Systems, Grade 6
- Water & Land Resources — Energy, Water & Material Resources, Physics & Environmental Science, Grade 12
In use
A watershed, also called a catchment, is every piece of land from which water drains to a particular point: a stream, a lake, or an estuary.
Watersheds, Water Quality & Sampling Limits
Questions using watershed
Problem 1
- One sample represents every place, season, and water-quality property.
- Clear-looking or filtered water is automatically safe to drink.
- watershed: An area whose drainage connects toward a common outlet under a defined landscape model.
- One illustrative result establishes every real condition and needs no further evidence.
Answer and explanation
watershed: An area whose drainage connects toward a common outlet under a defined landscape model.
An area whose drainage connects toward a common outlet under a defined landscape model. A’s mean dissolved oxygen is 8 mg/L; B’s is 5 mg/L. A has lower recorded turbidity under the stated method. These indicators support different physical/ecological comparisons, but the small record does not identify every cause, represent all seasons, or certify either water as safe to drink.
Problem 2
- a type of hydroelectric dam
- a machine that purifies drinking water
- the area of land that drains to a common body of water
- a large underground cave full of water
Answer and explanation
the area of land that drains to a common body of water
A watershed is all the land from which water drains into one shared river, lake, or bay.
Problem 3
- algal blooms and low-oxygen 'dead zones'
- cooler water temperatures
- an increase in drinking-water supply
- stronger bedrock beneath the lake
Answer and explanation
algal blooms and low-oxygen 'dead zones'
Fertilizer nutrients feed algal blooms; when the algae die and decompose they use up the oxygen, creating dead zones where fish cannot survive.
Problem 4
Answer and explanation
A watershed drains all the rain and runoff from its land into the reservoirs, so whatever happens on that land — pollution, sewage, erosion, or development — ends up in the water. By keeping the watershed forested and undeveloped, the soil and plants naturally filter and clean the water before it reaches the reservoir. Protecting the land therefore keeps the water clean without the cost of an artificial filtration plant.