Coverage of Early Warning System

Outcome

number of people covered by an effective early warning system (new or strengthened)

The indicator measures how many people live in areas that are covered by an effective early warning system (EWS). “Covered” means that it is expected that these people will receive an official warning in the event of a relevant hazard and that the system is designed to reach them through established procedures and communication channels. The indicator therefore reflects the theoretical coverage of the EWS: how many people could be reached if the system functioned as designed. It does not reflect how many were actually reached during a specific warning or disaster event.

Determine the indicator’s value by using the following methodology:

 

1) Define what counts as an “effective” early warning system in your context. A practical approach is to classify a system as effective if it meets at least three of the four core components of a functional early warning system:

• Understanding who is at risk (risk knowledge)

• Monitoring the hazard and forecasting potential events

• Disseminating warnings through reliable channels

• Supporting response actions (preparedness and ability to act)

 

2) Verify the presence of these components using a simple checklist during document review and key informant interviews. Questions could include:

• “How are hazards monitored, and how are alerts generated?”

• “How are warnings communicated to different groups in the target area? Which channels are used for which audiences?”

• “Who does what when an alert is issued - can you walk me through the steps?”

 

3) Identify the geographic areas covered by the functional system, in collaboration with local authorities, disaster management committees and meteorological or hydrological service.  Ask them to confirm:

• Where the system sends alerts - which villages, communities or towns are included

• Which hazards the system covers

If different systems or communication channels are used for different hazards, identify covered areas separately for each hazard.

 

4) Estimate the number of people living in covered areas using the best available administrative population data (e.g., figures from local authorities, census projections, or municipal registers). Count all residents in areas that the system is designed to reach. This represents the maximum number of people who should receive early warnings.

 

5) Verify whether the system is operational by reviewing documentation (e.g. Standard Operating Procedures, communication protocols), assessing existing equipment (sirens, SMS platforms, radio systems), and conducting key informant interviews (e.g. EWS operators and local DRM actors, including community representatives). Full technical testing is not required; the objective is to confirm that the system exists and functions as described.

 

6) To calculate the indicator’s value, sum up the total number of people living in areas covered by a functional EWS.

Disaggregate by location, whether the system is new or strengthened, type of hazard and other relevant criteria.

1) The indicator measures a theoretical coverage - i.e. the maximum number of people the system is designed to reach. In order to measure the actual coverage (i.e. how many people were actually reached), use the indicator Reach of Early Warning System.

  

2) Where possible, encourage local authorities or communities to carry out simulation exercises. This can help verify how well the system functions in practice and reveal any gaps in communication, coordination or inclusion. Simulation results support interpretation but are not required to calculate coverage.

 

3) If different systems cover different hazards (for example, floods vs storms), report coverage separately for each hazard to keep results clear and comparable.

 

4) Be aware that coverage estimates based on documents and key informant interviews may overestimate effective reach, particularly where last-mile communication is weak. Use relevant checklists (e.g., “Is there a tested channel in this community?”), triangulate information across 2-3 key informants, and interpret results conservatively.

 

5) When interpreting coverage results, consider whether certain groups may be systematically less likely to be reached in practice even if they live in areas classified as covered. Less-reached groups might be people with disabilities, older people, and people living in remote or isolated communities.