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The geography of Bangladesh - Formed by the alluvial (flat) plains of the Ganges-Brahmaputra river systems, the South Asian country of Bangladesh has always been vulnerable to extreme weather.

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The geography of Bangladesh - Most of the country lies less than 12 meters (about 39 ft) above sea level, and its land is criss-crossed by more than 230 of the most unstable rivers in the world.

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The geography of Bangladesh - This makes for terrain that is particularly prone to flooding and waterlogging, and as a result much of the country is underwater for up to eight months of the year.

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The effects of climate change - Bangladesh’s natural vulnerability to extreme weather conditions is compounded by climate change: flooding has intensified over the last few years.

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The effects of climate change - During monsoon season, much of the country’s farmland is completely submerged in water, making it impossible for farmers to grow and cultivate their crops.

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The effects of climate change - Even once the season has passed, the land remains waterlogged and farmers are still unable to grow the crops that feed their families and/or generate income.

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Move away from farming - As a result, many farmers are giving up their agricultural work and finding other ways to generate income. Some go to work in clothing factories, while others learn to farm shrimp.

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Floating gardens - But in parts of south-central Bangladesh, some farmers are choosing instead to revive the traditional cultivation method of “dhap” in order to keep their farms alive.

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Floating gardens - Dhap involves building floating gardens on which to grow vegetables. The gardens rise and fall with the movement of the water, and thus are immune to the effects of flooding.

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A centuries-old tradition and transition - Floating vegetable gardens have been around for the last 300-400 years, but there has been a renewed interest in them recently as a way to combat climate change.

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International solution -

Within Bangladesh, floating gardens are most common in the districts of Gopalganj, Barisal, and Pirojpur, but they can also be found in other areas of the world, most famously in Myanmar.

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Cultural importance - In December 2015, the UN’s Food and Agricultural Organization declared Bangladesh’s floating gardens a globally important agricultural heritage site.

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How to make a floating garden - The base of a floating garden is a type of raft, usually made out of water hyacinth. This is an invasive weed that is otherwise harmful to ecosystems and aquaculture.

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How to make a floating garden - If there is no water hyacinth available, other possible materials include straw, nalkhagra (a freshwater wetland tree), and any organic materials such as bamboo.

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How to make a floating garden -

To make the raft, sticks of bamboo are placed between two layers of water hyacinth, and then the materials are woven together. Once the structure is in place, the bamboo is extracted.

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Size - There is no standard size for a floating bed. However, they can be up to 55 meters (about 180 ft) long. A bed of that size could provide enough food for a family, plus extra to sell.

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Finishing touches - After seven to 10 days, more water hyacinth is placed on top of the raft. Soil, compost, and cow dung are then added to ready the raft for seed plantation.

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Seed preparation -

Before the seeds are planted, they must undergo a preparation phase that maximizes their chances of survival once planted in the floating bed.

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Seed preparation -

They are placed in small balls of peat soil called “tema” and wrapped in coconut fiber. After a week, when they are around 15 cm (5.9 in) tall, the crops are transplanted to the garden.

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Security - Once the seeds are safely planted, the farmers anchor their floating gardens in place with bamboo to make sure that they don’t float away.

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Getting around - During monsoon seasons, when water levels are particularly high, farmers often use a little boat when moving between the various floating islands.

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Vegetables grown - A typical floating garden lasts up to around six months and can be used to grow vegetables such as okra, gourd, and squash. Sometimes spices such as turmeric are grown.

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Earning potential - Floating gardens are cheap to create and therefore enable many farmers to grow crops throughout the year.

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Earning potential - The average cost of a floating garden is roughly 8,000 Bangladeshi taka (US$94), and, according to a report from the UN's Food and Agriculture Organization, farmers earn an average profit of $140 per 100 square meters of bed.

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Disposal of a floating garden -

At the end of the season when the beds are coming to the end of their lives, they are broken up and mixed with soil ready to grow winter crops like turnip and cabbage.

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Transportability - Floating gardens were traditionally popular in the south of Bangladesh, where conditions for creating them are optimal. But transporting them to other areas of the country is not easy.

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Transportability - In 2005, Care International and the International Union for Conservation of Nature attempted to implement the method in the north-eastern wetlands of Bangladesh, in swamp-like areas called “haors.”

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Transportability - Unfortunately, due to strong winds and water movements introducing floating beds to the haors was a real challenge. In 2020, they are still uncommon in northern Bangladesh.

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Going forward -

Even in the south of the country some people have concerns about the future of the cultivation method. The main worry is that they may not withstand more drastic climate change.

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Alternative methods -

Already farmers are experimenting with other options such as vertical farming and sandbar cropping, which involves filling holes in sand bars with compost and using them to grow pumpkins.

(BBC) (Practical Action)

See also: Will this be the first country destroyed by climate change?.

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