Maguindanao del Norte and del Sur sit around the Rio Grande de Mindanao and the Liguasan Marsh. Here is what to screen at an exact address.
Maguindanao del Norte and Maguindanao del Sur sit in the basin of the Rio Grande de Mindanao, the country's second longest river, with the Liguasan Marsh at its heart.
A marsh is not an accident of drainage. It is where water goes and stays, and the ground around it is ground that holds water.
For any address on the lowland, read these three together:
Flooding here tends to be broad and long-lasting rather than fast and violent. That means duration is the question to ask, not just depth. Half a metre for a week is a different event from half a metre for a night: the road goes, the crops go, the well is contaminated, and mould follows.
Ask neighbours two questions, always: how high, and how many days.
In late October 2022, Severe Tropical Storm Paeng (international name Nalgae) brought heavy rain to Mindanao. In Maguindanao, flash floods and debris flows in the Datu Odin Sinsuat area and elsewhere killed a large number of people.
That event is worth understanding precisely because it was not the slow basin flooding people were used to. Water came off the higher ground fast and carried material with it. See Paeng, October 2022.
The screening layer that speaks to this is the debris flow and alluvial fan flag, plus slope and the distance to the nearest channel. See the debris flow and alluvial fan brief.
Away from the basin, the land rises toward the boundaries with Lanao, Cotabato, and the coastal ranges. For any address on or below slope, read slope with mapped landslide susceptibility, and walk uphill from the property to look at the catchment above it.
Upland land use matters here as everywhere: cleared slopes shed water faster and supply more loose material. That is not a mapped layer and it is a question you can ask.
Datu Blah Sinsuat, Sultan Kudarat town, Parang and the Illana Bay shoreline are coastal. Screen mapped storm surge exposure against elevation for those addresses.
The Moro Gulf also has a documented history of a destructive tsunami following a large offshore earthquake in 1976. Tsunami is not a mapped layer on a screening and PHIVOLCS is the authority; the practical preparation is knowing where genuinely higher ground is and how long it takes to reach on foot. See tsunami and storm surge are not the same thing.
Land documentation in parts of the region can be complex, with overlapping claims and different systems in play. That is not a hazard question and it can be the more consequential one. Verify title and any restrictions with a licensed Philippine lawyer before you commit to anything.
A hazard screening reads public national datasets at a point and reports mapped susceptibility, elevation, slope, and distances. It does not rate tsunami, model the marsh, or measure soil at depth, and it has nothing to say about title. PHIVOLCS, the MGB regional office, a licensed geotechnical engineer, and a Philippine lawyer cover what it cannot.
CheckHazard does not replace a professional geotechnical or engineering survey.