the land area that supplies water to a river system is called

The land area that supplies water to a river system is called a watershed.

I agree with bob!!!

yes indeed.

The land area that supplies water to a river system is called the "watershed" or "catchment area." To determine the watershed of a specific river system, you can follow these steps:

1. Identify the river: Start by identifying the river system in question. This could be a major river like the Amazon or the Mississippi, or a smaller local river.

2. Locate the river's source: Find the source of the river, which is typically the highest point where water begins to flow downhill. This could be a spring, a lake, or even a glacier.

3. Trace the river backwards: Starting from the source, visually follow the river's path backwards, tracing all its tributaries (smaller streams or rivers that flow into the main river). Keep going until you reach the river's entire system.

4. Identify the land area: The land area that collects water and drains into the river and its tributaries is the watershed. It includes all the surrounding land, hills, mountains, and valleys from which water flows into the river system.

5. Define the watershed boundaries: Watershed boundaries are typically defined by the highest points of elevation known as divide lines. These divides separate one watershed from another.

Note that watershed boundaries can sometimes be quite large and encompass multiple states, provinces, or even countries, depending on the size of the river system.