, A.K.M. Saiful Islam

The Sundarbans is the largest deltaic mangrove forest in the world. Formed at estuarine phase of the Ganges-Brahmaputra river system, the forest covers approximately 10,000 km2, of which about 6,000 km2 are in Bangladesh and the rest are in India. It plays an important role in the national economy and the demand of its resources is increasing rapidly along with the population. This paper assesses the change in biomass concentration of the Sundarbans in Bangladesh from 1980 to 2009. The biomass concentration was assessed by estimating the normalized differential vegetation index (NDVI) as there is a correlation between biomass concentration and the NDVI. The study used four Landsat satellite images covering the entire Bangladesh Sundarbans, all acquired in the month of January in 1980, 1989, 2000 and 2009 respectively. It has been found that the mean NDVI value of the mangrove forest increased continuously during 1980-2000 from 0.31 to 0.56. However, in 2009, the mean NDVI value dropped to 0.52. The top 5 % of NDVI values ranged between 0.39-0.43, 0.57