DHAKA : Bangladesh needs a more accurate flood forecasting system, increased investment in disaster management and better urban planning to minimise losses from increasingly frequent floods driven by climate change and rapid urbanisation, experts have said.

Professor Dr. Md. Humayun Kabir, Dean of the Faculty of Earth and Environmental Sciences at the University of Dhaka, said strengthening the country’s flood forecasting and early warning system should be a priority as timely forecasts can significantly reduce casualties and economic losses.

“If reliable forecasts are available in advance, authorities can operate drainage pumps before water accumulates, emergency services can be mobilised and people can take precautionary measures to protect their lives and property,” he said.

He stressed that forecasting should be supported by modern weather monitoring technology, including fully functional weather radars, real-time rainfall and river monitoring and stronger coordination among agencies responsible for weather forecasting, water resources and disaster management.

Professor Humayun Kabir also called for increasing budgetary allocation for disaster management to improve forecasting capacity, strengthen preparedness and enhance emergency response.

He said the government should adopt long-term urban water management strategies by reconnecting Dhaka’s canals, wetlands and surrounding water bodies so that excess rainwater can be drained naturally during heavy rainfall.

According to him, years of unplanned urbanisation have disrupted the city’s natural drainage system through the encroachment of canals and wetlands, indiscriminate filling of ponds and low-lying areas and the loss of open green spaces.

To mitigate waterlogging in Dhaka, he suggested improving the drainage system, restoring degraded wetlands, maintaining and creating retention ponds, and promoting rainwater harvesting.

He also emphasised the need to promote rainwater harvesting as part of the country’s climate adaptation strategy.

“Rainwater should be treated as a resource rather than waste. If rainwater harvesting is promoted in public and private buildings, it will not only reduce waterlogging but also ease pressure on groundwater,” he said.

He suggested that the government begin implementing rainwater harvesting systems in major public institutions, including the University of Dhaka, before expanding the initiative nationwide.

Professor A.K.M. Saiful Islam of the Institute of Water and Flood Management (IWFM), Bangladesh University of Engineering and Technology (BUET), said Bangladesh experiences different forms of flooding, including urban floods, river floods, flash floods, hill-torrent floods and floods in low-lying plains, each requiring different management approaches.

Explaining the recent flooding, he said the event was triggered by a monsoon depression that transported a large volume of moisture from the Bay of Bengal into the eastern region of the country. As the moisture-laden air rose over the hills, it produced intense orographic rainfall.

“Chattogram recorded about 413 millimetres of rainfall in a single day recently and nearly 850 millimetres over three days, exceeding the carrying capacity of rivers and drainage systems,” he said.

Professor Saiful Islam said such extreme rainfall is becoming more common as climate change increases atmospheric moisture, resulting in more intense downpours.

He said heavy rainfall alone does not explain the severity of urban flooding. Rapid and unplanned urbanisation, encroachment on wetlands and canals, obstruction of natural drainage and poor solid waste management have significantly increased flood risks in cities, he said.

He noted that many drains have already lost a large share of their carrying capacity because they are clogged with garbage.

“No matter how many new drains are constructed, they will not function effectively unless existing drains are cleaned regularly and solid waste is managed properly with active public participation,” he said.

The experts also stressed the need for strict implementation of urban master plans, building regulations and zoning policies, alongside improved maintenance of drainage infrastructure and embankments.

They said accurate forecasting, science-based urban planning, restoration of natural water bodies, wider adoption of rainwater harvesting and stronger institutional coordination would together help Bangladesh better cope with the increasing risks posed by floods in a changing climate.