Which of the following best defines "flood risk management"?

"Flood risk management" is best defined by measures to reduce the likelihood and impact of flooding. This involves a comprehensive approach that encompasses various strategies aimed at identifying, assessing, and minimizing the risks associated with flooding. Effective flood risk management analyzes potential flood hazards, evaluates vulnerable areas, and implements preventive actions to mitigate the effects of flood events.

This definition emphasizes the dual focus on both prevention and preparedness, recognizing that while it's important to reduce the chances of flooding occurring, it is equally crucial to lessen the negative consequences for communities and ecosystems when floods do happen. It includes various practices such as land-use planning, flood forecasting and warning systems, community preparedness initiatives, and structural interventions like levees or flood barriers.

The other options do not accurately capture the essence of flood risk management. For example, promoting urban development might inadvertently increase flood risk if not managed carefully, methods to increase water flow could actually lead to higher flood risks, and improving drainage systems is only one component of a much broader flood risk management strategy. Thus, option B correctly encapsulates the comprehensive approach needed to address flood risks effectively.