Experts have predicted that Bangladesh is likely to face medium intensity flooding in August. At least 16 districts in the Meghna basin could be affected due to backwater impact as the water level of Meghna estuary is likely to rise, they said.
According to experts, downpours started early—three months back—in Bangladesh due to climate change which has the potential to trigger a medium intensity flood.
The average rainfall in the Indian state of Meghalaya, including in areas like Cherrapunji, stood at 13,500 mm, while the figure is 2,500mm for Bangladesh, they said.
“Heavy downpour occurred in the Meghna and Brahmaputra basins and there are also possibilities for more rainfall in these basins, as India’s met office predicted heavy downpour in Meghalaya area,” Dr SI Khan, former water expert of the UN, told The Independent yesterday.
He also said that the Ganges basin didn’t experience heavy downpour—so there is little possibility for any large-scale flood in these areas—but a medium intensity flood is likely in the Meghna and Brahmaputra basin areas.
The rain water is rolling into Bangladesh’s rivers from Meghalaya due to the construction of dams in Guwahati areas, he said, adding that the rain water are entering the haors of Sunamganj, Sylhet, Moulvibazar, Netrokona and Kishoreganj.
“The government has to take steps through construction of sabo-dam as the first line of defence to reduce velocity of flood water to save people’s property from erosion. Plantation of trees is also needed in erosion prone areas,” the river and water expert said.
He added that sea water levels have increased in coastal areas of Bangladesh. “So, if there are heavy downpours in the country—the water level of country’s rivers will also increase as it won’t be able to flow down to the sea, leading to floods,” he added.
Large-scale floods in Bangladesh is dependent on the level of upstream rainfall in India, said Dr Maminul Haque Sarker, deputy executive director of Center for Environmental and Geographic Information Services (CEGIS).
“Bangladesh will experience a big flood if water increases in the three basins—Meghna, Ganges and Brahmaputra—at the same time. But there has been no flooding in the Ganges basin as the downpour was not enough to trigger such a scenario,” he said.
According to Dr Sarker, there is currently no need to worry about a big flood in the country.
“There are possibilities of a medium intensity flood in August—but there is no major threat for the country. It is true there are heavy downpours in the upstream,” Md Shah Alam, former director of meteorological department told this correspondent.
He further said downpour started three months ago in Bangladesh due to climate change and it is difficult to predict the nature of climate—which can change any time.
A resurgent monsoon is becoming active over the country causing heavy rainfall in different parts overnight that continued even yesterday.
Till 12 noon, the heaviest fall was recorded in Cox’s Bazaar at 106mm, followed by 67mm in Teknaf, and 68mm in Maijdi court. Earlier, till 6am yesterday, Chittagong received the highest pounding of 159mm, according to met office sources in Dhaka, where it recorded 43mm at the same time.
Badalgachi in Naogaon received 57mm followed by 43mm in Dhaka. Bogura had 38mm. Tetulia to the far northwest had 48mm of rainfall.
The Met Office, meanwhile, issued a heavy to very heavy rainfall warning between 6pm of yesterday till 6pm of today at places over Rangpur, Mymensingh, Sylhet and Chattogram. The hilly regions in these two divisions may witness landslides because of the heavy rain.