Hydrologic Aspects of Flood Warning-Preparedness Programs

A reliable flood-threat recognition system is a vital component of a sound flood warning-preparedness program. Fundamental questions associated with the development of a flood-threat recognition system are: what warning times can be achieved, and how reliable will the warnings be? Answers to these questions depend on watershed and storm characteristics, and the flood-threat recognition method being considered. The tradeoff between warning time and warning reliability is illustrated, and methods for estimating warning time are discussed.