PETALING JAYA: Heavy rainfall expected during the Northeast Monsoon, which is expected to last from November till March 2022, could see parts of the country facing flash floods.
The Irrigation and Drainage Department (DID) said although floods occurred annually in identified at-risk areas during this season, other areas in the country could face flash floods as well.
Its director-general Datuk Nor Hisham Mohd Ghazali told Sunday Star that floods had been getting more frequent in recent years, especially in cities where rapid urbanisation was taking place.
The main causes of flooding in Malaysia, he said, were increased runoff rates due to urbanisation and loss of flood storage as a result of development extending onto flood plains and drainage corridors.
Inadequate drainage systems and river capacity, siltation in waterway channels from indiscriminate land clearing operations, and construction at bridges and culverts that were either undersized or partially blocked by debris build-up, would also lead to flash floods when coupled with localised continuous heavy rainfall, he added.
“The increased rainfall is expected to result in floods as rivers and drainage systems struggle to accommodate, causing cliffs to overflow, affecting low-lying settlement areas.“In preparation, DID carries out maintenance work on rivers, flood reservoirs and other DID infrastructure,” said Nor Hisham.
The National Disaster Management Agency (Nadma) estimates that 4.8 million people live in flood-risk areas throughout the country.
According to the International Federation of Red Cross and Red Crescent Societies, about 9% (approximately 29,800 sq km) of the land area in Malaysia is prone to flooding, with large floods occurring in the northern states, especially in November and December.
Records from the Meteorological Department (MetMalaysia) show no significant change in the country’s average annual rainfall rate at this time compared to five or 10 years ago.
However, Malaysia might potentially face new weather phenomena, including extreme weather, if global warming and environmental pollution were not properly addressed, said MetMalaysia director-general Muhammad Helmi Abdullah.
An increase in extreme weather occurrences such as stronger thunderstorms and heavy rains could lead to major flash floods, he said.
“MetMalaysia will continue to carry out comprehensive observation, monitoring and forecasting of the country’s weather and climate by providing relevant information to stakeholders in dealing with the threat of climate change,” he added.
