Question

The longitudinal profile of a stream is typically _________. The lowest elevation below which a stream cannot cut is called its ________ and occurs at the stream's _________.

a) convex-up / water table /
source
b) convex-up / base level / mouth
c) concave-up / base level /
mouth
d) concave-up / tributary / source

Answer 1

The longitudinal profile of a stream is concave-up and the lowest elevation a stream can cut to is its base level, occurring at the stream's mouth. The correct option is c.

Step-by-step explanation:

The longitudinal profile of a stream is generally concave-up. The lowest elevation below which a stream cannot cut is called its base level and occurs at the stream's mouth.

Therefore, the correct answer for the question posed is (c) concave-up / base level / mouth. The profile shape is due to the fact that streams have a steeper gradient at their source and a gentler slope near their mouth.

The base level is the lowest point upto which a stream can explode. This is commonly at the point where the stream enters a larger body of water, like an ocean, lake, or another river.