Certified Storm Water Operator Practice Exam

Which of the following factors does NOT contribute to soil slippage?

1. Moisture content

2. Steepness

3. Temperature

4. Bonding

The correct answer is: Temperature

The factor that does not contribute to soil slippage is temperature. Soil slippage, or landslides, primarily occurs due to the interplay of moisture content, steepness of the slope, and bonding characteristics of the soil particles. Moisture content influences the weight of the soil and can reduce friction between soil particles, making it more likely to slide. Steepness is crucial because as the angle of the slope increases, the gravitational forces acting on the soil mass become more pronounced, increasing the likelihood of slippage. The bonding between soil particles helps maintain soil structure; when bonding is weakened, this can lead to instability. Temperature, while it can affect other environmental processes (like the expansion and contraction of materials), does not directly cause soil slippage. Changes in temperature may influence the moisture content indirectly through processes like evaporation or freeze-thaw cycles, but the temperature itself does not create the conditions necessary for soil to slide.