Flash flood may turn into early monsoon flood

The flash flooding of north-eastern districts and chars in the northern region may turn into early monsoon floods as forecasters see no end to extreme rain anytime soon.

Department of Agricultural Extension in its latest advisory on Sunday asked farmers in the north to take home their boro harvest regardless of their maturity to protect their crops from imminent flooding.

Rivers in the north are still below their danger marks but their rapid swelling has already submerged 17,645 hectares of standing boro crop, mainly in chars dotting northern rivers such as the Teesta, reported New Age correspondent in Lalmonirhat.

Boro was grown on 156,980 hectares in the five districts of the Rangpur division. The rapidly rising northern rivers also impacted other crops cultivated on 9,312 hectares, DAE said.

At least 27 houses were washed away by the Teesta in the division between Sunday and Monday, confirmed the divisional office of the Water Development Board.

Water submerged several villages after flood protection embankments at three places in Rangpur, Lalmonirhat and Kurigram gave in during the period.

But rivers in the north-eastern haor area seemed to be exploding with water as flood monitoring stations reported that at least seven rivers overflowed their banks in Netrakona, Sunamganj, Habiganj and Sylhet districts on Monday afternoon.

The north-eastern rivers are carriers of runoff from a massive mountainous terrain, home to the world’s wettest place such as Meghalaya, where 1,344 per cent excess rainfall compared to what is normal was recorded in the 24 hours until 9:00am Bangladesh time.

There has been incessant rain in north-east India for about two weeks now but Meghalaya usually does not see so much rain during this period as it did between Sunday and Monday.

‘The frightening news is that we do not see a dry weather spell anytime soon,’ meteorologist Bazlur Rashid told New Age.

‘The weather will continue to remain wet for as long as weather models can predict,’ he said.

Rainfall particularly picked up upstream across the border in India and inside Bangladesh after the cyclonic storm Asani, formed in the Bay of Bengal.

Intermittent extreme rain continued in north-east India and inside Bangladesh since May 9. Torrential rain already triggered landslides and flooding in Assam and Meghalaya, killing five people, according to Indian media.

The US-based The Weather Channel on Monday warned that rain was unlikely to spare northeast India anytime soon with heavy to extremely heavy rain lashing the region through Friday.

In the 24-hour until 9:00am Bangladesh time on Monday, the IMD also reported 375 per cent above-normal rain in Assam, followed by 220 per cent above-normal rainfall in Sikkim, 192 per cent above-normal rain in West Bengal, 175 per cent above-normal rain in Arunachal Pradesh and 146 per cent above-normal rain in Manipur.

While the Teesta drains runoff from West Bengal and Sikkim, which received over 800 per cent above-normal rain just a few days back, the Brahmaputra is affected by rains in Assam and Arunachal Pradesh.

The Padma is also rising, according to Flood Forecasting and Warning Centre.

The FFWC said that Jaflong, which is torn by three waves of flash flooding already, received 286mm of rain in the 24 hours until 9:00am on Monday, followed by 105mm of rain recorded at Chhatak of Sylhet.

There are at least seven places in northeastern and northern districts, where 50mm or above rain was recorded over the reporting period.

Out of 109 river gauging stations, 79 reported swelling in the water levels over the 24-hour reporting cycle.

The Surma was flowing128 cm above the danger limit, followed by Kushiyara flowing 110cm above its danger level, among other rivers, according to the FFWC.

The FFWC in its flood bulletin issued on Monday afternoon warned that the flood situation in low lying areas in Sylhet might worsen over the next 24 hours.

The spell of extreme rain persists amid reports of monsoon advancing towards land from the Bay of Bengal. The advance means incursion or more moisture into the atmosphere, the fuel for rain.

Meteorologically, the monsoon begins in June and lasts through August.

‘There is definitely going to be heavy rain in the last week of May,’ said Arifuzzaman Bhyuan, executive engineer, FFWC.

Bangladesh drains water from a vast area spanning India, Nepal, and Bhutan through its river systems. But rivers are exhausted from encroachment and siltation.

The arbitrary release of water by India through barrages upstream also made the management of floods complicated for deltaic Bangladesh, especially during monsoon.

News Courtesy:

https://www.newagebd.net/article/170728/flash-flood-may-turn-into-early-monsoon-flood