Context

Nearly a quarter of Bangladesh has been inundated with floodwaters, according to latest satellite images of the country captured by NASA recently.

Background

• Bangladesh has been a vulnerable state for much of its short existence.
• People in this flood-prone country have coped with rising water levels with a combination of innovation, flexibility and resilience – but the extremes the environment is now throwing at them might be beyond anyone’s endurance.
• As climate change accelerates, the pressures on rural Bangladeshis mount.
• Historically, people in Bangladesh had worked around seasonal flooding; farming for part of the year and retreating when water levels rose, or seeking work in the cities as land became unusable.
• By the end of the century, however, sea levels are expected to rise along the Bangladesh coastline by up to 1.5m.
• And that will come with more extreme seasonal fluctuations in sea levels. Disastrous storms and unusually high tides currently occur once each decade, but could become as regular as three to 15 times each year by 2100.
• As a result, rural Bangladeshis face a stark choice; change their way or life or seek employment and a home elsewhere.

What NASA has found?

• Images acquired by NASA show the scale of flooding, and were recorded over more than a month between June 2 and July 25.
  

*Water appears navy blue and black; clouds are white or cyan; and vegetation is bright green.

• The image captured on July 25, 2020, shows an enormous patch of blue on the map, where floodwaters have inundated.
• In the June 2 photo, the blue patch is much smaller as flooding had only just begun then.
• More than four million people have been affected and at least 100 had died in Bangladesh as of July 28.
• Most of Bangladesh is low-lying and is drained by the Ganga (Padma), Brahmaputra (Jamuna) and Meghna rivers and their tributaries.
• It is the longest-lasting flooding in Bangladesh in 1988, and has been termed the worst flooding in a decade.
• The Bangladesh Flood Forecasting and Warning Centre reported water levels along the Jamuna River were at or above “danger level” as of July 31.
• Almost a million homes were inundated and more than 1,500 square kilometres (600 square miles) of farmland were damaged across the country. Several areas are also isolated due flooded roads, it added.
• The country has not been able to prepare well for the monsoon this year as much of the flood-prevention infrastructure like embankments and dykes destroyed in earlier monsoons has not recovered yet.

The current situation in Bangladesh

• The physiography of Bangladesh is characterized by two distinctive features: a broad deltaic plain subject to frequent flooding, and a small hilly region crossed by swiftly flowing rivers.
• Bangladesh is crisscrossed by 230 rivers, including 53 shared with India.
• A four-month monsoon season, from June through September, routinely inundates this riverine country.
• Meanwhile, a quarter of Bangladesh’s landmass, bound on the south by the northern Indian Ocean, hovers less than seven feet above sea level.
• And as floods grow increasingly frequent and severe, the 163 million who make their home in Bangladesh, the world’s most populous delta, know little escape from water.
• Often referred to as “ground zero for climate change,” Bangladesh ranked sixth on the 2018 Global Climate Risk Index, and for many Bangladeshis, particularly the rural communities in low-lying coastal areas, those risks are already unmanageable. 
• Riverbank erosion displaces 50,000 to 200,000 people here each year. Thousands more flee every time a major cyclone hits the coast.
  
  

Is monsoon the reason behind the situation?

• Monsoons in Bangladesh are intense, with over 80 per cent rain taking place during the season between June and October.
• The country receives most of its rainfall during the summer — June to October.
• Even though flooding is common during these months, this year’s water damage has been particularly devastating.
• Downpours during monsoon season are nothing new. Rains beat down across much of South and East Asia every year from late spring through early fall, when the region sees temperatures and moisture levels increase and a seasonal change in the direction of prevailing winds.
• The wet period has historically provided an important relief from the relentless dry heat of summer, cooling the air and quenching thirsty crops and wildlife.
• But in recent years, amid the climate crisis, monsoon season has gotten far worse. Last yearwas the first monsoon season in recorded history to not begin its withdrawal by October 1, and the severity and length of this year’s floods are also remarkable.
• The United Nations has estimated that this year’s flooding could be the most prolonged since 1988.

What is the reason behind this?

• Riverbank erosion is the primary cause of climate displacement inland. Up to 50% of those now living in Bangladesh’s urban slums may be there because they were forced to flee their rural homes as a result of riverbank erosion.
• Those who live on Bangladesh’s river islands, known as chars, are especially at risk. Located within some of the world’s most powerful river systems, chars can be formed or completely eroded over weeks or even days.
• River flooding is also a cause of displacement inland, and along with erosion is likely to become more significant under climate change, as rainfall both increases and becomes more erratic, and the melting Himalayan glaciers alter river flows.
• As rainfall patterns change, the drier north-western regions of Bangladesh are at risk of drought, which drives people away through destruction of crops and disruption of livelihoods.While not currently a major factor in displacement, this risk is expected to rise as climate change progresses.
• Landslides, also induced by increasingly erratic rainfall, affect the hilly north-eastern and south-eastern regions of Bangladesh and can cause displacement by destroying homes and property, and disrupting agriculture.
  
  

  Rivers, the midwives of Bangladesh Rivers are the midwives of Bangladesh. The Ganges and Brahmaputra pour from the Himalayas and converge with the Meghna River to form the world's fourth largest drainage, which flows into the Bay of Bengal. Monsoon rains routinely put a quarter of the country underwater. The flooding brings hardship, but it also nurtures the rice that feeds one of the most densely populated nations on Earth. The country itself is born from those rivers. An estimated 1 billion tons of sand and silt flow downstream every year and settles in the delta, counteracting relentless erosion. Geologically, Bangladesh is a giant sandbox, 90 meters deep in places.

Conclusion

Bangladesh, a vast river delta that barely rises above the sea at the best of times, is buffeted by natural forces including flooding rivers and cyclones blowing in from the bay. Over decades, the country has developed defenses: warning systems, storm shelters, salt-resistant crops, and 139 polders near the coast—a 5700-kilometer network of walls to protect farmland from inundation. But humanmade infrastructure is not infallible and can cause problems of its own. As climate change becomes a reality with rising seas and stronger storms, there is need of strong measures.