A stream begins at an elevation of 200 metres and flows a distance of 400 kilometres to the ocean.What is the average gradient?
A)2 m/km
B)2 km/m
C)0.5 m/km
D)0.5 km/in

Question

Quizplus · Accepted Answer

Gradient is the change in elevation divided by the horizontal distance. The change in elevation is from 200 metres to sea level, which is 0 metres. Therefore, the change in elevation is 200 metres. The horizontal distance is 400 kilometres, which is equivalent to 400,000 metres. 
Gradient = change in elevation / horizontal distance
Gradient = 200 metres / 400,000 metres
Gradient = 0.0005 = 0.5 m/km

A Stream Begins at an Elevation of 200 Metres and Flows