Section 4: Soil and Water Conservation Engineering
Soil and Water Erosion
Subtopic: Mechanics of soil erosion – wind and water erosion
Question Statement:
Watershed erosion data: R=280 MJ·mm/(ha·h·yr), K=0.38 t·ha·h/(MJ·mm), slope length=200 m, average slope=8%, LS-steepness factor=0.85, C=0.35, P=0.60. If slope length is halved, find the percentage reduction in soil loss (using the USLE slope-length exponent m=0.5 for slopes ≥5%). (Rounded to 2 decimal places)
Official Answer Key:
29.10 to 29.50
Step-by-Step Solution & Explanation
Soil loss (USLE) ∝ L^m with m=0.5 for slopes ≥5%. Halving L changes the length-factor ratio to (0.5)^0.5 = 0.7071 of its original value (all other USLE factors unchanged). Percentage reduction = (1−0.7071)×100 ≈ 29.29%.
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.