Section 4: Soil and Water Conservation Engineering
Soil and Water Erosion
Subtopic: Terraces and bunds
Question Statement:
A bench terrace system is constructed on a hillside having a land slope $S = 20\%$. The vertical interval is $VI = 2.0\text{ m}$. The terrace risers have a slope of $1:1$ (riser horizontal width equals $VI = 2.0\text{ m}$). The cultivated bench width $W_b = \frac{100 \cdot VI}{S} - VI$ in metres is ________ (answer in integer).
Answer Key:
8
Step-by-Step Solution & Explanation
1. Total horizontal spacing between terrace steps:
$W = \frac{100 \cdot VI}{S} = \frac{100 \times 2.0}{20} = 10.0\text{ m}$
2. Cultivated bench width deducting the riser footprint ($1:1$ slope $\implies 2.0\text{ m}$):
$W_b = W - VI = 10.0 - 2.0 = 8.0\text{ m}$