What conditions produce the most surface water runoff?

The conditions that produce the most surface water runoff occur when there is a steep slope, heavy rain, and frozen ground. In this scenario, the steep slope facilitates faster movement of water down the incline, as gravity has a greater influence on water flow. Heavy rain contributes to a substantial volume of water quickly saturating the surface, which limits infiltration into the ground, especially when the ground is frozen and unable to absorb the water.

When the ground is frozen, it creates an impermeable barrier, preventing water from percolating into the soil, which means that instead of soaking into the ground, the water flows over the surface, resulting in increased runoff. The combination of these factors leads to a significant increase in the volume of surface runoff compared to other scenarios, such as gentle slopes or dry ground, which would allow for greater water infiltration.

Thus, the combination of steep terrain, substantial rainfall, and frozen conditions maximizes surface runoff, making the choice about steep slope, heavy rain, and frozen ground the most accurate in describing conditions that lead to increased surface runoff.