NOAH, PHIVOLCS, MGB, PAGASA, NAMRIA. Five names that get used interchangeably and should not be. Here is who does what.
When people say "the hazard map", they are usually talking about one of several different products from several different agencies, built for different purposes.
Knowing which is which saves you from asking the wrong office and from over-reading an answer.
The Philippine Institute of Volcanology and Seismology. The authority on earthquakes, active faults, volcanoes, and tsunami.
PHIVOLCS maintains the active fault map, sets volcano alert levels, defines permanent danger zones, assigns earthquake intensities, and issues tsunami information. If your question is about a fault, a volcano, or shaking, PHIVOLCS is the answer, and no other source overrides them.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration. The authority on weather: tropical cyclones, wind signals, rainfall warnings, storm surge warnings, seasonal outlooks, and climate projections.
PAGASA tells you what the weather will do. It does not tell you what your lot does. See PAGASA rainfall warnings and your address and wind signals explained.
Project NOAH began as a government programme and now sits with the University of the Philippines. It produces the modelled hazard maps most commonly used for flood, landslide, and storm surge susceptibility, at national scale.
These are the layers that let a screening say "this point falls inside a mapped high flood susceptibility polygon". They are models of where hazard is expected, not records of where events happened.
The Mines and Geosciences Bureau, under DENR. Produces geohazard assessments, typically at the level of municipalities and barangays, covering landslide and flood susceptibility and, in some areas, karst and sinkhole concerns.
MGB assessments are the ones LGUs commonly hold, and the regional offices are the right place to ask about local geological concerns that national models do not carry.
The National Mapping and Resource Information Authority handles base mapping and topography. The Philippine Statistics Authority publishes administrative boundaries. Neither is a hazard authority; both supply the frame everything else is drawn on.
A CheckHazard report does not produce hazard data. It reads the public datasets those agencies publish, at your exact coordinates, and reports what they say in one place.
That is the whole product: not new science, but a point-level read of existing public science, with the sources named. The full source list and licences are on the data licensing page, and the thresholds are on the methodology page.
| Your question | Ask |
|---|---|
| Is there an active fault near this lot? | PHIVOLCS |
| What is the volcano's alert level today? | PHIVOLCS |
| Is a typhoon coming, and what signal? | PAGASA |
| How much rain is forecast? | PAGASA |
| Is this barangay flood or landslide prone? | MGB regional office, and the LGU |
| Is the property in a declared no-build zone? | The city or municipal government |
| Where is the evacuation centre? | The barangay and the local DRRM office |
| What does the soil do at depth here? | A licensed geotechnical engineer |
| Will this house stand up in a quake? | A licensed structural engineer |
Two failures are common.
Treating a model as a record. A susceptibility map says where hazard is expected. It is not a list of past floods, and a place outside a polygon can still have flooded.
Treating a screening as an authority. A screening reports what published datasets say. When PHIVOLCS raises an alert level or an LGU declares a zone, that is the operative fact, not what a report printed last month.
A hazard screening is a reading of other people's published data. It is only as current and as detailed as those sources, and it never overrides the agency that produced them. Where a screening and an agency disagree, the agency is right.
CheckHazard does not replace a professional geotechnical or engineering survey.