Calculate the drainage density of a river basin if the total length of all streams in the basin is 120 km and the basin area is 2000 km².

Step-by-step solution

1. Step 1: Write the formula for drainage density: $D=\frac{L}{A}$, where $L$ is total stream length and $A$ is basin area.
2. Step 2: Substitute the given values: $D=\frac{120\text{ km}}{2000{\text{ km}}^2}$.
3. Step 3: Perform the division: $120÷2000=0.06$.
4. Step 4: State the units: since length is in km and area in km², density is in km⁻¹.
5. Step 5: Write the final answer: $0.06{\text{km}}^{-1}$.

Concept tested: Drainage density calculation

Published 7 October 2026 · How this solution was prepared and checked