What is the term for the rate at which rain falls, expressed in inches per hour?

The term that refers to the rate at which rain falls, expressed in inches per hour, is known as rainfall intensity. This measurement is crucial in hydrology and stormwater management because it helps engineers and planners understand how quickly rainwater will impact the drainage systems and the potential for runoff. Rainfall intensity can influence design considerations for stormwater management systems, including detention basins, retention ponds, and drainage channels.

In contrast, while precipitation rate may generally refer to the amount of rain that falls over a period, it does not specify the intensity at which the rain falls. Storm rate and hydraulic rate are not standard terms used to denote this specific measurement of rainfall intensity. Understanding rainfall intensity is essential for effective design and management of urban infrastructure to manage stormwater effectively and reduce flooding risks.