Pakar ITB Ungkap Penyebab Banjir Sumatera, Termasuk Hilangnya Resapan

[music]

Floods in three provinces on

Sumatra Island have claimed 442 lives

and hundreds of others are missing.

The scale of this disaster has the public

wondering what the triggering factors were.

According to ITP atmospheric expert, Dr. Muhammad

Rais Abdillah, there are a number of factors that

triggered flash floods and landslides on

Sumatra Island since November 24, 2025.

Quoted from the ITB website, Dr. Rais

explained that this event occurred

due to complex interactions between

atmospheric factors, geospatial conditions, and the

region's carrying capacity.

According to Dr. Rais, the

northern part of Sumatra is currently entering

the peak of the rainy season with

rainfall distributed twice a year.

The BM foot recorded rainfall above 300

mm which is categorized as

extreme rainfall.

The phenomenon of a developing senile cyclone

in the Strait of Malacca strengthens the supply of

water vapor and the formation of rain clouds, thus

expanding the precipitation area in

North Sumatra.

Meanwhile, ITB spatial gas expert,

Dr. Harry Andreas explained that

flooding is also influenced by how water is

received, absorbed, and managed by the

earth's surface. In other words, it's not

just about high rainfall, Dr.

Harry explained that when infiltration or

water enters low-lying areas, the water

immediately becomes runoff or flows

quickly into rivers and ultimately triggers

flooding.

Therefore, Dr. Heri highlighted

the loss of catchment areas such as forests

and swamps that should act as

natural barriers to water runoff. Changes in

land use into settlements, plantations,

and open areas without vegetation cause the

soil to lose its absorption capacity.

Doctor Hari emphasized that flood mitigation

cannot only rely on embankments

or river normalization. According to him,

mitigation must be based on spatial planning,

conservation of catchment areas and

accurate geospatial modeling.

Furthermore, Dr. Rais also

emphasized the importance of early warnings that are

scientifically accurate, communicative, and

easily understood by the public to

reduce the impact of future casualties

.