Final answer:
The statement that soil creep is faster on water-saturated slopes is true due to reduced friction and cohesion between soil particles in moist conditions, facilitating the downward movement of soil.
Step-by-step explanation:
The statement that soil creep is generally faster on water-saturated slopes than on dry ones is true. This is because the additional water within the slope material reduces the friction and the cohesion between soil particles, making it easier for the soil to move downwards under the influence of gravity. This process can be exacerbated during a thaw, where previously frozen moisture in the soil melts, leading to increased movement as observed in solifluction. Additionally, when soil is saturated and water flow is present, it can lead to an increase in mass wasting events such as mudflows, which can incorporate soil, rocks, and organic material and move it down the slope rapidly.