Pre-monsoon floods in haor areas may cause food crisis by 2050
Bangladesh is likely to face a severe food crisis by 2050 as pre-monsoon flooding in the country's northeast haor areas might lead to a sharp fall in Boro output, according to experts.
"There will be frequent pre-monsoon flooding in hoar areas because of shift in rainy season due to climate change, taking its toll on Boro output," Emaduddin Ahmed, a water expert and Executive Director of the Institute of Water Modelling (IWM), told UNB.
He said waterlogging during April-June period, the high time for Boro cultivation, will become too common because of irregular and erratic heavy rainfall.
There are nearly 57 haors in Sylhet, Sunamganj, Moulvibazar, Habiganj, Netrakona and Kishoreganj districts, a northeast region of the country known for boro cultivation. But flash flood damages huge crops here during harvest every year.
Emaduddin said, "Even if the farmers cultivate boro crops in time, they won't be able to harvest their yields due to flash flood to be triggered by heavy rains and onrush of waters from hills."
He stressed the need for reconstruction of crop protection embankments in haor areas by raising their heights.
SM Shah Newaz, a flood management expert, said the rainfall will increase by 10-15 percent in the haor areas for “global circulation”, triggering flash flood.
Citing the record of rainfall in Assam and Meghalaya, India, he said nearly 14,000 mm of rainfall are recorded at Cherrapunji in Meghalaya every year and it will increase in the future. "The rainwater from hills in India will also hit Bangladesh's haor areas before monsoon.”
About the present condition of the haor protection embankments, he said the existing embankments are not enough to protect boro crops because the river water level in the areas will increase by 0.6 metre by 2050.
"The haor protection polders will be rebuilt raising their heights by 1 metre to save boro crops from rainwater," he said.
More worrying is that this haor region will become a permanent bowl of water as there will be no chance for the rainwater to run off due to rise in river water level, Shah Newaz said.
According to him, the polders will have to be reconstructed using modern technology apart from setting up pumps to pump out water to ensure smooth cultivation of boro crops.
"We know that a large amount of the country's food comes from the haor region. If we can't ensure proper boro cultivation in the haor areas, the country will face a severe food crisis by 2050," the flood management expert said.
A recent study by the IWM shows that the water level in the country's northeast haor areas during pre-monsoon period will rise by 0.3 to 0.6 metre by 2050.
The water level in the Karchar Haor in Sunamganj will rise by 0.3 metre and in the Kawardighi Haor of Moulvibazar by 0.6 metre, according to the study.
The study recommended that the existing haor protection embankments will have to be raised by 1 to 1.5 mertres to save paddy fields from flooding during the boro season.
The study also suggested reassessing and redesigning the flood embankments, including submergible embankments in the haor region.
It says that an integrated approach of river management covering dredging of the navigational routes and river bank protection along with feasible interventions can be undertaken to protect boro crops from the pre-monsoon flood.
Sources at the Bangladesh Water Development Board (BWDB) said the six districts have 367 kilometres of embankments to protect 46 haors from recurring floods.
Experts estimate that an amount of Tk 2,500 crore will be needed to implement a comprehensive project for remodelling the existing embankments to save boro crops in the six districts from flash floods.
Climate expert Dr Atiqur Rahman said the incidence of flood in Bangladesh has marked a rise by 20 percent in recent years due to climate change, dealing a blow to food grain production in the country's low-lying areas like haor.
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