A design storm is not characterized by which of the following?

A design storm is primarily characterized by factors such as the duration of rainfall, the return period, and the intensity of precipitation. Each of these components plays a crucial role in the analysis and design of stormwater management systems.

The duration of rainfall refers to how long the storm is sustained, influencing the total volume of water and the timing of peak discharges in a given area. The return period is a statistical measure used to describe the likelihood of a storm of a certain intensity occurring within a given timeframe, allowing engineers to predict future rainfall events based on historical data. Intensity of precipitation is essential in determining design parameters because it indicates how much rain falls over a specified duration, impacting the rate of runoff and the capacity required for drainage systems.

Runoff in a channel, however, is not a direct characteristic of a design storm itself. Instead, it is a response to the precipitation event and the characteristics of the watershed. While understanding runoff is essential for designing effective water management solutions, it is the result of applying various characteristics of the design storm, rather than a defining feature of the storm. Thus, it is not included as a characteristic in the definition of a design storm.