Impact of climate on Sunderbans famed mangroves
The Sundarbans is a vast forest in the coastal region of the Bay of Bengal which is one of the natural wonders of the world. Located in the delta region of Padma, Meghna and Brahmaputra river basins, this unique forest area extends across Khulna, Satkhira, Bagerhat, Patuakhali and Barguna districts. The Sundarbans is the largest forested forest in the world, as the largest mangrove forest in the coastal environment. Sunderbans, which has a population of 6,017 sq km in 10,000 square kilometers,is in Bangladesh. In 1997, Sundarban was recognized as UNESCO World Heritage Site.
- The mangrove forest cover in the Indian Sunderbans has been depleting alarmingly over the past few decades.
- The total forest cover of the Indian Sunderbans as assessed by remote sensing studies for the year 1986 was about 2,246.839 sq. km., which gradually declined by 2,201.41 sq. km. in 1996, then down to 2168.914 sq km in 2001 and to 2122.421 sq km in 2012. The loss in the mangrove forest in the Indian Sunderbans is about 5.5 %.
“The continuation of this process in response to climate change and sea level rise poses a serious threat to the carbon sequestration potential and other ecosystem services of this mangrove forest in future,” authors Sugata Hazra and Kaberi Samata noted”.
Bird eye view of Sunderbans report
- The mean sea level rise at the Sagar Island Station, measured from 1985 onward till 2010, shows a rise by 2.6-4 mm a year, which can be considered a driving factor for coastal erosion, coastal flooding, and an increase in the number of tidal creeks.
- It highlights a time series of the erosion of at least 18 mangrove forested islands of the Indian Sunderbans from 1986 to 2012. For instance, the loss in mangrove cover at Gosaba has been about 20%, down from 517.47 sq km in 1986 to 506.691 sq km in 2012.
- In Dulibhasani West, the loss of mangrove cover has been about 9.7% — from 180.03 sq. km. in 1986 to 163.475 sq. km. in 2012. The mangrove forest cover of Dalhousie, another island, has depleted by 16%, from 76.606 sq. km. in 1986 to 64.241 in 2012. Bhangaduni has one of the highest erosion levels of mangrove forest land, from 40.4 sq. km. in 1986 to 24.9 sq km in 2012, taking the loss to over 37%.
- Jambudwip, one of the smallest uninhabited islands at the mouth of the sea, also has reduced forest cover from 6.095 sq. km. in 1986 to 5.003 sq. km. in 2012, or about 10%.
- Other islands like Sajnekhali North, Matla and Bulchery have also suffered significant mangrove loss.
Explanation by head of School of Oceanographic Studies, Jadavpur University.
How climate change and sea level rise has contributed to the phenomenon of losing land?
This is because there is less fresh water flow and sediment supply in the western (Indian) part of the delta, so we have starvation of sediment and the rate of sea level rise is higher than sediment supply. Hence we are losing land, including mangrove forest.