An ominous trend | The Daily Star
12:00 AM, September 08, 2017 / LAST MODIFIED: 01:27 AM, September 08, 2017

SPOTLIGHT

An ominous trend

Statistics related to floods and cyclones display a dramatic increase in intensity in the last three decades in Bangladesh and experts fear that the trend is likely to get worse.

As far as food security is concerned, 2016 was a great year for Bangladesh. The confidence of the government was so high that it had actually put in place a plan to export 40-50 lakh tonnes of rice in May last year.

However, 12 months on, the scenario is different. Ever since the floods devastated the Haor region, the country's main breadbasket, in March this year, Bangladesh has been frantically working on deals to import rice from Vietnam, Cambodia, India and a couple of other countries.

Just when you think you have a surplus amount of food and there is no cause for concern, in comes a devastating flood that compels you to import in order to stay afloat. It just goes on to show how crippling the effect of severe climatic disasters, such as floods, can be.

Photo: Ziaul Haque Oisharjh

Drastic increase in flood coverage

An analysis of the flood statistics in Bangladesh displays an ominous trend. Numbers from the Bangladesh Water Development Board (BWDB) suggest that the intensity of floods—when the flood coverage is taken into account—in Bangladesh has been increasing with time.

In the last 30 years, from 1987 to 2017, the country witnessed seven floods that inundated or devoured more than one-third of the nation. Prior to that, between 1956 to 1986, this benchmark was surpassed just once, in 1974.

Each of these floods has caused plenty of destruction and havoc, and the increase in frequency is not good news.

In between 1980 to 1990, more than 35 percent of the nation went under water twice, first in 1987 and then in 1988. In 1987, close to 40 percent of the country was under water, while more than 60 percent of the nation was below water in 1988.

The period between 1990 and 2000 witnessed a more threatening trend. From 1995 to 2000, the country witnessed floods, which consistently inundated more than 20 percent of the country every year. This includes the disastrous floods of 1998, which saw 70 percent of the country drown. These were by far the worst floods Bangladesh had ever witnessed.

In between 2000 and 2010, 40 percent of the nation went under water in 2004 and 2007. The assessment period for this year is still underway, but it is certain that more than 40 percent of the country has already been affected in 2017. There is a fear that  this number may increase.

Dr Atiq Rahman, Executive Director of Bangladesh Centre for Advanced Studies (BCAS) and an eminent climate expert, agrees that floods are becoming more and more intense every year. He, however, bases his statement on more than just the flood coverage factor. According to him, the intensity of the flood also depends upon how badly the agricultural products are affected.

He highlights the recent floods in the Haor region, to explain his point.

“Had the floods arrived to the Haors a little later, the farmers would have cut their crops and they wouldn't have worried about the chest-high water. They would, on the contrary, be happy and singing baul songs because they would have gotten a bumper crop and that would have helped them live without any worries for three years. There are plenty of factors to consider,” he says.

Photos: Ziaul Haque Oisharjh

Lack of preparedness

He attributes the recent floods in the country to climate change and states the examples of Rangpur and Dinajpur regions which witnessed the worst ever floods in the last three decades. 

“There was an unprecedented amount of water from the Tibetan Plateau, particularly from the slope coming from Nepal. The rainfall from Nepal and China gushed in during the last few days. The erratic rainfall and sharpness of the rapid flow were factors that were unprecedented. That's why I call it climate change. It goes beyond the variability of 30 years,” explains Dr Atiq.

The lack of preparedness hurt these two places a lot more than the other areas.

“A woman in Kurigram, for instance, will keep dry wood on the rooftop before the season of the floods, because she knows that no matter what happens, she will have to cook. She has a transportable chula.

“But can you expect people in Dhaka or Dinajpur to be like that? The amount of water that came into Rangpur and Dinajpur was unexpected. The floods in that region were not knee-high, not chest-high, but double the human height,” says Dr Atiq.

“This was also the time before Eid and so they were fattening their animals. Their investment got affected badly. So that just made everything worse,” he adds.

Photos: Ziaul Haque Oisharjh

Cyclone windspeed on the rise

It is not just floods that are displaying an increase in intensity. Tropical cyclones have also shown a similar trend.

One of the most crucial factors for measuring the intensity of a cyclone is its wind speed. According to data from the SAARC Meteorological Research Centre (SMRC), between 1991 and 2009, Bangladesh witnessed five cyclones with a maximum wind speed of above 200 kph. On the contrary, between 1901 and 1990, the country had witnessed just one cyclone, in November 1970, which crossed the 200 kph barrier. This goes on to show that severe cyclones, or cyclones with high speeds, were a lot rarer in the early 1900s.

Again, the amount of destruction or the number of casualties isn't exactly proportional to the increase in wind speed. For instance, the Bangladesh cyclone of 1991, which had a wind speed of 225 kph, reported more than one lakh casualties. Six years later, another cyclone hit the coast of Chittagong with a maximum windspeed of 230 kph. That cyclone, however, witnessed 155 deaths. What these numbers do show is that over the years Bangladesh has improved its resilience to cyclones with a systematic safety approach.

Bangladesh's latest tryst with cyclones was when Mora threatened the country at the coast. The highest possible warning signals were displayed in all the coastal areas and people expected the worst. However, fortunately, the cyclone made landfall during the low tide, which significantly decreased the effect.

Dr Atiq explains that the increase in wind speed over the years is a result of climate change.

“The earth's temperature has been gradually increasing ever since the pre-industrial era. As the temperature rises, evaporation increases and the cloud formation has a higher amount of water vapour. It carries more weight. It's like how a heavy-weight boxer packs a bigger punch than a light-weight boxer,” he says.

Aside from causing casualties and plenty of destruction, cyclones also push salt water into the fresh water areas in the coast, which increases the salinity of the water and in turn affects the farmers. Several farmers are then forced to quit their age-old profession and come to the city in order to support themselves.

Photos: Ziaul Haque Oisharjh

Erratic rainfall

Aside from cyclones and floods, the changing pattern in rainfall is also adversely affecting the country. Professor AKM Saiful Islam, who works at the Institute of Water and Flood Management in the Bangladesh University of Engineering and Technology (BUET), explains the erratic rainfall pattern.

“Our study shows that consecutive wet days will decrease in the future, although the total amount of rainfall in the country will increase. Therefore, the intensity of the rainfall will increase in the future, which can lead to an increase in extreme events such as flash floods,” he says.

What he basically means is that while the total amount of rainfall in Bangladesh has not decreased, the intensity has increased because there's more rain arriving in a shorter period of time.

This change may not only cause extreme events such as floods, it can also affect the farmers who plan what to grow based on the season.

Professor Saiful adds that there is a chance that the Haor regions may witness more flash floods.

“Many studies have already shown the connection between global warming and the changes in the frequency of certain extreme events on a global scale. Our studies have also shown the likely increase of the extreme precipitation in the Haor areas; consequently, flash floods could increase in the future. However, more extreme event attribution studies should be conducted to establish that global warming has added to the severity of flash flood events,” he says.

Floods in South Asia this year have killed more than 1000, affected at least 40 million and prevented more than a million children from going to school. Let's not forget it has compelled Bangladesh's agriculture ministry to change its strategy within just a year.

One wonders what more it will take to change the mindset of certain influential world leaders, responsible for a large portion of the carbon up there in the atmosphere, who still don't seem to believe that climate change is real. Numbers related to cyclones and floods don't lie and it's quite clear that drastic measures need to be taken in order to ensure that these statistics don't reach a point of no return.

Read the other half of this week's Spotlight: How flows become floods

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