Aside from meteorological factors, the country's weather bureau cited other causes of flooding, which include rapid urbanization and development.
During the "MAGHANDA: Communicating Hazards, Risks, and Early Warning for Policymakers" event on Tuesday, Jan. 23, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) said that urbanization caused the abrupt rise of flood water during rain events, particularly in Metro Manila.
Weather Specialist Facilities II Adelaida Duran said 80 to 100 percent of flood or rainfall water seeps through the ground prior to urbanization, with the remaining 20 percent passes through waterways.
However, due to urbanization in Metro Manila, she said all rain water must pass through the drainage system, which has "limited" capacity.
Duran emphasized that there are "inadequate" flood control structures because the drainage capacity was only designed to handle 60 to 80 percent of the flood water.
Furthermore, she said that clogging in Metro Manila's drainage laterals and waterways contributes to flooding because it "impedes the conveyance of water."
Duran also highlighted the effects of environmental degradation, specifically the act of cutting portions of the Sierra Madre mountains, which resulted in flooding during typhoons.
Meanwhile, she said that PAGASA uses a "cheaper" non-structural approach called the Flood Forecasting and Early Warning System to keep people away from floods.