Which of the following is not a factor influencing the times of concentration of watershed runoff?

The times of concentration for watershed runoff refers to the time it takes for water to travel from the most remote point in a watershed to the outlet. This is influenced by various factors, including land use, rainfall intensity, and slope of the land.

Land use plays a critical role because different types of land cover (such as urban, agricultural, or forested areas) interact with precipitation in distinct ways, affecting the speed at which water runs off. For instance, impervious surfaces in urban areas can lead to faster runoff compared to permeable surfaces in natural landscapes.

Rainfall intensity affects how quickly water will accumulate in a watershed. Heavy rainfall can lead to a rapid increase in runoff compared to light, steady rain, which allows more water to infiltrate the ground before it contributes to surface runoff.

The slope of the land directly influences how quickly water can flow across the surface. Steeper slopes tend to promote quicker runoff as gravity aids the movement of water towards lower elevations.

Since land use, rainfall intensity, and slope significantly influence runoff characteristics, stating "none of the above" indicates that all options provided are indeed factors affecting times of concentration, making it the correct answer.