Flood Warning - Description

Description

The task of flood warning divided into two parts:

• decisions to escalate or change the state of alertness internal to the flood warning service provider, where this may sometimes include partner organisations involved in emergency response;
• decisions to issue flood warnings to the general public.

The decisions made by someone responsible for initiating flood warnings must be influenced by a number of factors, which include:

• The reliability of the available forecasts and how this changes with lead-time.
• The amount of time that the public would need to respond effectively to a warning.
• The delay between a warning being initiated and it being received by the public.
• The need to avoid issuing warnings unnecessarily, because of the wasted efforts of those who respond and because a record of false alarms means that fewer would respond to future warnings.
• The need to avoid situations where a warning condition is rescinded only for the warning to be re-issued within a short time, again because of the wasted efforts of the general public and because such occurrences would bring the flood warning service into disrepute.

A computer system for flood warning will usually contain sub-systems for:

• flood forecasting;
• automatic alerting of internal staff;
• tracking of alert messages and acknowledgements received;
• diversion of messages to alternates where no acknowledgement received.