Which of the following is a common cause of erosion on construction sites?

The disturbance of soil is indeed a common cause of erosion on construction sites. When the soil is disturbed—whether through excavation, grading, or other activities—it loses its natural structure and cohesion. This disruption makes the soil more susceptible to erosion by wind and water. Without protective vegetation or ground cover, exposed soil can easily wash away during rainfall or be displaced by wind, leading to significant erosion issues.

Other factors, like the installation of drainage systems or the use of heavy machinery, can contribute to erosion but are not as direct in causing the issue as soil disturbance itself. Effective vegetation cover serves as a natural barrier against erosion, helping to hold soil in place through root systems and preventing sediment loss. Therefore, the primary factor leading to erosion on construction sites is the act of disturbing the soil itself, making it the correct choice.