Watersheds
Introduced| English |
|---|
| watershed/ˈwɔːtəʃed/ |
| divide/dɪˈvaɪd/ |
| runoff/ˈrʌnɒf/ |
Where the water goes
- When rain falls on a hillside, it flows downhill and collects.
- All the rain in one area ends up in the same river.
- That whole area of draining land is a watershed.
- Watersheds connect everyone who shares the same water.
What a watershed is
- A watershed 流域 is all the land that drains its water to a single river or lake.
- Rain falling anywhere in it flows to the same outlet.
- Big rivers have huge watersheds made of many smaller ones.
- Every point on land belongs to some watershed.
A watershed is…
A watershed is the whole area of land that drains its water to one common outlet.
The divide
- Two neighbouring watersheds are separated by high ground.
- This high boundary is called a divide 分水岭.
- Rain on one side of the divide flows to one river; rain on the other side flows to another.
- A ridge or mountain crest often marks the divide.
The high ground separating two watersheds is called a…
A divide (usually a ridge) separates the land that drains into different watersheds.
Water flowing over the land surface into rivers is called ____.
Runoff is rain that flows over the surface and collects in the watershed's river.
Everything is connected
- Rain becomes runoff 径流 that carries soil, nutrients, and pollutants along.
- Because the whole watershed drains to one place, actions upstream affect everyone downstream.
- A factory or farm upstream sends its pollution down to those below.
- This is why protecting a watershed protects everyone who uses its water.
Inside or outside the watershed?
Sort each idea by whether it correctly describes a watershed.
Pollution added upstream in a watershed can travel downstream to everyone below.
A watershed connects everything by water, so upstream pollution flows down to those below.
Select all true statements about watersheds.
How the land is used strongly affects the watershed's water. The other three are correct.
In a watershed, upstream and downstream are linked. Pollution added anywhere upstream — fertiliser, sewage, waste — flows down to every community below. You cannot pollute "your part" of a river without affecting everyone downstream who shares the same watershed.
A shared river:
- A town dumps waste into a river near the top of a watershed.
- The waste flows downstream, past farms, cities, and wildlife.
- Every community below is affected — which is why watersheds are often managed together, not town by town.
A watershed is all the land that drains its water to a single river or lake, separated from its neighbours by a divide. Rain becomes runoff that carries materials downstream, so upstream actions affect everyone below. Protecting the whole watershed protects everyone who shares its water.