What study focuses on a watershed's behavior during and after a storm?

The study of hydrology is concerned with the movement, distribution, and properties of water within the Earth's atmosphere and on its surface. When focusing on a watershed's behavior during and after a storm, hydrology will examine various factors such as precipitation, runoff, infiltration, evaporation, and storage of water. It analyzes how water interacts with the land and how it flows through different landscapes, including how watersheds capture and channel water during storm events.

Understanding these dynamics is crucial for effective floodplain management and mitigation strategies, as it helps in predicting flood patterns, evaluating water resource availability, and planning for stormwater management. Thus, hydrology is fundamental in analyzing a watershed's response to storm conditions, making it the correct choice for this question.