Compare the two records
You are given two sketches of sealed sample jars before and after standing still. Both start brown. After an hour, jar A has a brown layer at the bottom and clearer water above it. Jar B still looks evenly coloured. Write down what changed before deciding what caused it.
Draw a narrow conclusion
The layer in jar A is evidence that particles settled. Jar B might contain finer particles that need longer, dissolved colour or both. It tells you that you did not see the same settling in that hour. It does not tell you why on its own.
Read the river through the model
In a fast reach, particles can stay mixed with the water. In quiet water farther downstream, some can settle. You can use the jar as an analogy for one part of that journey, while remembering that a river is continually carrying material in and moving it onward.
For the underlying idea, read why a river turns brown after rain. Explore more routes in the water cycle hub.
Read the source: US Geological Survey · Sediment and suspended sediment.