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Human interaction caused land cover changes of Chakaria Sundarban mangrove forest in
Bangladesh: a fifty-years study
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1 Mehedi Hasan, Leion Hassan, Mamun Abdullah Al*, Mohammad Ziaul Hoque, Riffat Mahmoood,
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5 Ataher ali, Nahin Alam, Abu Hena Mustafa Kamal
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1 Department of Oceanography, University of Chittagong, Chittagong 4331, Bangladesh.
2 Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban
Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei
Road, Xiamen 361021, China.
3 University of Chinese Academy of Sciences, Beijing 100049, China.
4 Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, Kuala Nerus, 21030
Terengganu, Malaysia.
5 Department of Fisheries, University of Chittagong, Chittagong 4331, Bangladesh.
6 Department of Agricultural Extension and Rural Development, Bangabandhu Sheikh Mujibur Rahman
Agricultural University, Gazipur-1706, Bangladesh.
7 Department of Geography and Environment, Jagannath University, Dhaka 1100, Bangladesh.

* Corresponding author: abdullah@iue.ac.cn

Abstract:
Chakaria Sundarbans is one of Bangladesh's oldest and second-largest mangrove forests. Due to tremendous
human interference, this forest ecosystems have been vulnerable in recent decades. In this study, we
investigate the rate of successive land cover changes of Chakaria Sundarbans, Bangladesh using remote
sensing approaches. We have collected data from five multi-temporals Landsat satellite imageries for 1972,
1990, 2000, 2010 and 2020, respectively, to observe the land use land cover (LULC) changes. Using the
supervised classification technique with the help of support vector machine (SVM) algorithm in ArcGIS,
our results showed that the image for 1972’s was classified into three categories, namely mudflat,
waterbody and mangrove forest. While images of 1990, 2000, 2010 and 2020 were classified into four
groups as waterbody, mangrove forest, saltpan and shrimp farms. Our results showed that 64.2% area was
covered by mangroves forest in 1972, but it was found 12.7%, 6.4%, 1.9% and 4.6% for 1990, 2000, 2010
and 2020, respectively. We observed that the net increase of saltpans and shrimp farms was 40.9% and
41.9% from 1972 to 2020, respectively. The kappa coefficients of classified images were 0.83, 0.87, 0.80,
0.87 and 0.91 with the overall accuracy of 88.9%, 90%, 85%, 90% and 93.3%, respectively. Furthermore,
the normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI) and transformed
difference vegetation index (TDVI) showed that green mangrove vegetation has been gradually decreased
over the time. Our study showed that the relationship between NDVI and SAVI was relatively stronger than
those of NDVI and TDVI. Therefore, findings of this study highlighted that human activities significantly
influence mangroves forest alternation and would decrease coastal ecosystem services.

Keywords: Land use land cover change, Human activities, Mangroves, ArcGIS, Chakaria Sundarbans