The Promissory Tale for the Sunderbans

Gautam Kumar Das

Rural major populace dwelling in the Sunderbans are engaged in deforestation in the course of farming and fishing to enhance the domain. River bed sedimentation and accretion causing inundation and overflow of the creeks, rivers and estuary is an important reason of decline of the world famous Sunderbans mangroves. Survey shows that during the last century more than 5000 sq. km of mangrove forest area were cleared to make way for human settlement. Several hectares of mangroves vegetations at Basanti, Gosaba, Sahebkhali, Sandeshkhali, Canning, Jharkhali, Patharpratima, Kakdwip, Namkhana, Raidighi, Rakhhaskhali, Buraburir Tat, Bakkhali, Sagar Island, Maipith, Kaikhali, Jambudwip and other areas are on the verge of decline. Both the state and central government should be more active to protect mangrove forests from being destroyed. Apart from implementation of law, awareness campaign to restore ecosystem should be strengthened. Meanwhile, the state government has launched an awareness campaign highlighting the current role of mangroves to provide safety against the tsunamis, super cyclones like natural disaster. Once the mangroves of the Sunderbans are lost, they will be lost forever. Large stretches of mangroves of Sunderbans are still neglected, even though this world heritage site gets the attention for conservation by the Government. It seems even at present that the local people and the Government are still unaware of the significance of the mangrove community.

The British Government started protection of the forest of the Sunderbans and about 4690 sq km of 24 Parganas (undivided) district alone was declared as protected forest. The British foresters realized the role of mangroves to protect Calcutta metropolis, the then capital of the British India from the devastating effects from the violent cyclones. They understood that the mangroves, the green wall of the coast, served as the natural protection systems.

The Department of Space, Government of India has mapped the mangroves area of 4474 sq km using satellite data in 1987. This mangrove area data seem to be anomalous to a little bit because of mixing colour combination in the satellite data with that of the social forest regenerated by the forest department bordering the reclaimed area of the human habitated zone. Department of Environment, Government of India along with Space Application Center, Ahmedabad, India has estimated 4266.6 sq km mangrove covering area of the Sunderbans in 1996, out of which about 1952.87 sq km is covered by dense mangroves forest and 226.18 sq km has been covered by sparse mangroves leaving the remaining part covered with waters of rivers, tidal inlets and creeks.

Estimation of mangroves covering areas of 4282.38 sq km of the Sunderbans in 1999 through GIS study (Table 1) after being digitized and geo-referenced of the imagery has been computed for the 24 Parganas (South) Forest Division and Sunderbans Tiger Reserve using IRS 10, Liss III data of 22nd December, 1999 in 4 bands (green, red, near IR and SW IR) supplied by NRSA, Hyderabad. The classification areas of dense mangroves, open mangroves, sand and grass in hinterland, non-forest use, clear water, muddy water are shown in the handbook on Sunderbans Biosphere Reserve in 2003.

Table 1 Classified mangrove covering areas of the Sunderbans

Computation of forest areas of the Sunderbans including land and water is worked out through remote-sensing technique with the cooperation of the Department of Space, Government of India through GIS study of digitized and geo-referenced of satellite imagery-data with 83 – 90% accuracy. Comparative analysis of satellite data vis-à-vis old stock maps prepared by Mr. Curtis, a British forester (1924-29) shows a loss of about 220 sq km of land area within the reserved forest of the Sunderbans over a period of about 60 years from 1929 to 2003 (Tables 2, 3 & 4) due to erosion by waves and tidal actions as reported in a handbook on Sunderbans Biosphere Reserve in 2003. The analysis also reflects the sites of erosion at Dhoblat area of Sagar Island, southern part of Jambu Island, south eastern part of Gosaba and 4 and 5 no. compartments of Mayadwip. On contrary, accretion is taking place at Chuksar Island, southern part of Sagar Island, Saptamukhi and Thakuran.

Table 2 Comparative studies of areas of the forest blocks under 24 Parganas (South) Forest Division between 1948 and 2003

Table 3 Comparative studies of areas of the forest blocks under Sunderbans Tiger Reserve (STR) Forest Division between 1948 and 2003

Table 4 Comparative studies of areas of the forest blocks under Sunderbans Reserved Forest between 1948 and 2003

The natural afforestation gradually emerging on chars (islands), point bars, marginal bars, natural levees and mid channel bars even in the different areas of the estuarine river basins of the Indian Sunderbans is going on. Improvement of mangrove canopy with luxuriant vegetation has been detected through GIS Study. Discontinuity of permit for wood harvesting simultaneously with afforestation programme, the mangrove areas start increasing around 3% in the entire areas of the Indian Sunderbans, whereas, increase of approximately 23% of the mangrove areas of the forest block of Thakuran alone is the highest among all the blocks of 24 Parganas (South) and Sunderbans Tiger Reserve (STR) within a span of 70 years from 1948 to 2003. The tale of this survey speaks with a promissory fact for the Indian Sunderbans.

People of Sunderbans, singly a homogenous entity are not enough to protect the Sunderbans. Further, these poor and working people, the worst victims of the damage to this productive ecosystem are given priority to save this tidal forest through awareness programmes. The fight against exploitation of the poor people along with their unemployment, illiteracy and poverty is to be integrated as a part of the fight against the exploitation of the Sunderbans as a whole. Afforestation programme may be taken in the turtle back shaped central portion of islands, typical of Sunderbans, particularly the plantation of Hental (Phoenix paludosa) which will be growing better in these substrate soils lacking soil-moisture and befitted for the denizen of the world famous Royal Bengal Tiger. Government policy for digging up of artificial canals traversing top of these islands in order to increase soil moisture for growing up of mangroves in the central portion of the islands are not useful as because tidal water flowing through these artificially made canals never inundate the elevated top of the island, although the canal banks will be covered with the mangroves regeneration. Plantation of some fruit-bearing fresh water plants may be useful on the top, elevated, turtle back shaped island but this might have the negative impact on the restoration of gene pool of the mangroves and the mangrove associated species. The people may save the Sunderbans, even conserve it and expand through afforestation, only if they have the alternate source of income and improvement of their livelihood surrounding their constraint environment. Mangroves of Sunderbans need now immediate conservation through proper schemes and policy in the Government level.

Nov 09, 2017