Mangroves low tide made cyclone bulbul less devastating

Mangroves low tide made cyclone bulbul less devastating

When Cyclone Bulbul hit south Bengal districts last weekend, it was more fierce than Cyclone Aila that had ravaged south Bengal districts, a decade ago. The highest wind speed clocked by Aila was 110-120 kmph, while that by Bulbul was 130 kmph, nearly 10 kmph more. Yet unlike Aila, which had killed scores of people and left lakhs of people homeless, the death toll and destruction caused by Bulbul was much lower — 22 in West Bengal and Bangladesh vis-a-vis nearly 340 in 2009.

Environmentalists thank this to two factors — the low tide and mangrove forest of Sunderbans that withstood the brunt of Cyclone Bulbul.

According to them, as Cyclone Bulbul approached, the mangroves impeded the wind, proving yet again its importance in safeguarding coasts from storms that are becoming increasingly more frequent and more severe due to climate change.

“No doubt that Sundarban mangroves have been partially saved during Bulbul as high tide did not coincide with the cyclone’s landfall like what happened during Aila, which had made it far more dangerous… Low tide helped a lot and mangroves worked as the second barrier, which absorbed the major devastating force of the cyclonic storm,” said Kalyan Rudra, chairman of West Bengal Pollution Control Board.

Due to low tide, the wave heights were significantly lower this time as it was during the 2009 Cyclone Aila. The landfall of Aila during high tide meant the destruction of many more embankments in 2009. Experts said that had there been a high tide this time, more embankments and dam would have damaged, making the situation severe and maybe even more devastating than Aila.

G K Das, director of IMD’s regional office in Kolkata, added one more factor to the less devastating effect of Bulbul. According to him, one of the reasons why the damage to the area beyond the Sundarbans was less during Bulbul than during Aila was the movement of the cyclone. According to him, Cyclone Bulbul moved from west to east parallel to the coast, through the mangrove forest. In contrast, Aila had moved northwards, crossing the Sundarbans relatively quickly.

The state government, too, seem to have realised the significance of the mangrove in nullifying Bulbul’s effect. “You don’t forget that mangrove forest saved us a lot. If there is no mangrove forest then, the devastation will be more and embankments will damaged more. Then more seawater will enter into the Sundarban area,” Chief Minister Mamata Banerjee told officials at Basirhat on Wednesday.

According to officials at the state secretariat, the state government had realised the importance of mangroves after Cyclone Aila, and since then efforts were made to increase the forest cover in the Sunderbans.

“After Aila, we started to increase ‘Jhau bon’ plantation along the embankments. The then Sundarban Development Minister Kanti Ganguly helped a lot and regularly told villagers to increase the forest cover. That helped Sundarbans to grow as a wall to save us from such cyclonic storm… This time, the forest, therefore, helped to absorb the intensity of the storm,” the official said.