The catastrophic flash flood in Nepal has shown how quickly debris flows can overwhelm communities, a danger that also exists in the Philippines.

University of the Philippines Resilience Institute-National Operational Assessment of Hazards Center (UPRI-NOAH) Executive Director Mahar Lagmay said the Philippines also faces the threat of debris flows, although the trigger can be different from what happened in Nepal.

The Nepal incident was most likely triggered by a glacier collapse, while extreme rainfall is the more likely trigger for debris flows in the Philippines.

Lagmay said more than 1,000 areas  in the country have now been identified as potential sites for debris flows, up from just a little over 100 previously, through the use of science and technology and the best available tools.

Many communities are located on alluvial plains because these areas have fertile land and access to rivers and other water resources that support agriculture and livelihoods.

Flooding also replenishes the soil with sediments and nutrients.

“Gusto ng mga tao yon. There's a natural tendency for them to live in hazardous areas (People want to stay in those areas. There's a natural tendency for them to live in hazardous areas),” Lagmay said during a press conference on Thursday, Aug. 27.

According to Lagmay, the Philippines has its own history of destructive debris flows.

In December 2012, debris flows overwhelmed Barangay Andap in New Bataan, Compostela Valley during Super Typhoon Pablo, killing 566 people and burying parts of the community under several meters of debris.

He also cited Gabaldon, Nueva Ecija, where Typhoon Lando triggered debris flows in 2015 that damaged homes and other structures, although warnings and evacuation helped prevent deaths.

Baco, Oriental Mindoro, was another example, where debris flows struck during Typhoon Nona in 2015.

“There are more than 1,000 places where there are communities, and we need to put them out of harm’s way. And if we cannot get them to be in that place, at least we need to get them prepared,” Lagmay said.

The challenge is that debris flows do not happen often, making it harder for communities to recognize the danger before one occurs.

“Di naman kasi araw-araw nangyayari yung debris flow, but we can get them to understand that there's a problem so that they know. Kasi if they don't know, chances are they will get surprised. And if there are many people who get surprised, it turns into what we call as a disaster (Debris flows do not happen every day, but we can get them to understand that there's a problem so that they know. Because if they don't know, chances are they will get surprised, and if there are many people who get surprised, it turns into what we call as a disaster),” he said.

Lagmay pointed out that the goal is to address the risks while finding safer ways for communities to live alongside natural hazards.

“We want to solve that problem. We want to do better and be smarter in living with nature,” he said.