Kidapawan, Makilala, Tulunan, Digos: this part of Mindanao was shaken hard in October 2019, and some of the movement happened where no fault was mapped. What that means for a buyer checking one address.
Land in North Cotabato and Davao del Sur is cheaper than the equivalent near a big city, the ground is fertile, and the highlands are cooler than the coast. Buyers who move here for those reasons often check flood and stop. In October 2019 this area got a hard reminder that shaking belongs on the list too.
A series of strong earthquakes struck the Tulunan and Makilala area of North Cotabato within weeks of each other. Damage reached Kidapawan and across into Davao del Sur towns like Digos and Magsaysay. Buildings failed, and slopes failed too: the shaking set off landslides on hillsides that had looked stable for a lifetime.
Two things in that sequence are directly useful when you are looking at a lot.
The first is that repeated shaking does cumulative work. A structure that survives the first event can be weakened enough that a second one finishes it. That is an argument about how you build and what you inspect on an existing house, not just about where you buy.
The second is more uncomfortable. Ground effects showed up in places where no fault trace had been published before. A map of known faults is not a map of every fault. Our report measures the straight-line distance from your coordinates to the nearest mapped active fault, using the PHIVOLCS and GEM dataset, and bands it: inside 100 metres is very high, inside 500 metres high, and inside 2 kilometres moderate. Those bands are honest about known traces and cannot describe a fault nobody has mapped yet. The layer brief is at Active Faults.
The building and the ground decide the outcome, not the magnitude number. Most Philippine houses are not engineered for a strong quake, and the ones that are usually got that way because someone paid for a design rather than by accident. That is covered in most Philippine homes are not built for a big quake.
The ground matters just as much in three ways worth checking one by one.
This region is not all highlands. The Pulangi and Mindanao river systems drain a large area, and the flat land near those channels floods in the ordinary way: rain falls faster than the ground and drains can move it, the river rises, low ground fills first. Read the flood level and the return period together, because a Level 3 rating in the 5 year scenario is a different property from the same level appearing only in the 100 year scenario. Also read distance to the nearest mapped waterway: inside 20 metres is very high, inside 50 metres high, inside 150 metres worth noting.
On volcanoes, the sensible move is to work from the number rather than from the skyline. Mount Apo dominates the boundary between the two provinces and it is very visible from a lot of these towns, which makes people either worry about it constantly or dismiss it entirely. Our report measures the straight-line distance to the nearest volcano on the PHIVOLCS list and bands it: inside 10 kilometres is high, 10 to 30 kilometres is moderate, and 30 to 100 kilometres is low and mostly an ashfall consideration. Get the number for your address and stop guessing. Buyers comparing this area with the city can look at the Davao City profile.
Screening works from mapped, modelled data. For faults, that means known traces; the 2019 sequence in this exact area is the clearest possible argument for reading a Low fault finding as "no mapped trace nearby" rather than as "no shaking here." Everywhere in the Philippines can shake. Distance to a known fault changes how hard and how likely, not whether.
The hazard polygons are also regional in scale, so they describe a neighbourhood better than one 200 square metre lot, and they cannot see a retaining wall, an unfinished drainage line, or uncompacted fill. What a screening does is tell you quickly whether this is a property where those questions are worth a professional''s time and fee.
CheckHazard does not replace a professional geotechnical or engineering survey.