Mapping tidal channel dynamics in the Sundarbans, Bangladesh, between 1974 and 2017, and implications for the sustainability of the Sundarbans mangrove forest
- 409 Downloads
This study presents the spatial and temporal dynamics of tidal channels in the Bangladesh Sundarbans. Parts of the Passur River system were considered for this investigation. Tidal channel bank layers were extracted from aerial photographs from 1974 and 2011 and a Sentinel-2 image from 2017. On-screen digitizing of a tidal channel was undertaken to create the tidal channel layers, and special care was taken during digitization to obtain more accurate results. Layers were overlaid together so that the tidal channel position could be seen for each date. Tidal channel positions were highlighted to infer the erosion/accretion sectors along the channel, and the tidal channel dynamics were calculated. Remote sensing and Geographic Information System (GIS) platforms were used to analyse, interpret and visualize data on accretion and erosion, as well as the locations of the tidal channel bank over different years. The results revealed that erosion was severe in the larger channels, whereas accretion was dominant in the smaller channels. These erosion and accretion processes played an active role in the displacement of tidal channel banks during the period under investigation. Displacement of the tidal channel bank has had a profound impact on the Sundarbans mangrove ecosystem, and continued erosion and accretion processes are of concern for the future sustainability of biodiversity in the Sundarbans. While in the short term, these changes may not have much impact; over decades, the dynamics of tidal channels may significantly contribute to the imbalance of fauna and flora in the Sundarbans.
KeywordsPassur River system Erosion and accretion GIS On-screen digitizing Aerial photographs
We acknowledge the Survey of Bangladesh (SOB) for the provision of aerial photographs used in this study.
M.K.G., L.K. and P.K.L. conceived and designed the experiments; M.K.G. performed the experiments and analysed the data. M.K.G. wrote the paper, with support from L.K and P.K.L.
Compliance with ethical standards
Conflicts of interest
The authors declare that they have no conflict of interest.
- Ali, A. (1996). Vulnerability of Bangladesh to climate change and sea level rise through tropical cyclones and storm surges. In L. Erda, W. C. Huq, S. Lenhart, S. K. Mukherjee, & J. Wisniewski (Eds.), Climate change vulnerability and adaptation in Asia and the Pacific (pp. 171–179). Netherlands: Springer.CrossRefGoogle Scholar
- Allison, M. A. (1998). Historical changes in the Ganges-Brahmaputra delta front. Journal of Coastal Research, 14, 1269–1275.Google Scholar
- Begum, K. (1987). Tension over the Farakka Barrage: a techno-political tangle in South Asia. Dhaka: Dhaka University Press.Google Scholar
- Chatterjee, N., Mukhopadhyay, R., & Mitra, D. (2015). Decadal changes in shoreline patterns in Sundarbans, India. Journal of Coastal Sciences, 2, 54–64.Google Scholar
- Danda, A. (2010). Sundarbans: future imperfect climate adaptation report. New Delhi: World Wide Fund for Nature—India Available at http://assets.wwfindia.org/downloads/sundarbans_future_imperfect__climate_adaptation_report.pdf. Accessed 23 Oct 2016.Google Scholar
- Das, G. K. (2004). Morpho-dynamics of deltaic Sunderbans rivers. Geomorphology and environment (pp. 303–308). Kolkata: Acb Publications.Google Scholar
- Day, J. W., Boesch, D. F., Clairain, E. J., Kemp, G. P., Laska, S. B., Mitsch, W. J., Orth, K., Mashriqui, H., Reed, D. J., Shabman, L., Simenstad, C. A., Streever, B. J., Twilley, R. R., Watson, C. C., Wells, J. T., & Whigham, D. F. (2007). Restoration of the Mississippi Delta: lessons from hurricanes Katrina and Rita. Science, 315(5819), 1679–1684.CrossRefGoogle Scholar
- Hassan, S. T., Syed, M. A., & Mamnun, N. (2017). Estimating erosion and accretion in the coast of Ganges-Brahmaputra-Meghna Delta in Bangladesh. Available online: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Estimating+erosion+and+accretion+in+the+coast+of+Ganges-Brahmaputra-Meghna+Delta+in+Bangladesh.+&btnG=. Accessed 10 July 2016.
- Islam, S., & Gnauck, A. (2009). Threats to the Sundarbans mangrove wetland ecosystems from transboundary water allocation in the Ganges basin: a preliminary problem analysis. International Journal of Ecological Economics and Statistics (IJEES), 13, 64–78.Google Scholar
- Islam, M. T., Broström, G., Christensen, K., Drivdal, M., Weber, J., Shendryk, I., & Alwmark, C. (2014). Vegetation changes of Sundarbans based on Landsat imagery analysis between 1975 and 2006. Landscape Environment, 8, 1–9.Google Scholar
- Mahadevia, K., & Vikas, M. (n.d.). Climate change—impact on the Sundarbans. Available online: https://scholar.google.com.au/scholar?q=climate+change-impact+on+the+Sundarbans&btnG=&hl=en&as_sdt=0%2C5 . Accessed 12 Dec 2016.
- Roy, A. (2010). Vulnerability of the Sundarbans ecosystem. Journal of Coastal Environment, 1(2), 169–181.Google Scholar
- Stanley, D. J., & Warne, A. G. (1998). Nile Delta in its destruction phase. Journal of Coastal Research, 14, 795–825.Google Scholar
- Wadman, H. M. (2008). Controls on continental shelf stratigraphy: Waiapu River, New Zealand. Virginia: The College of William and Mary.Google Scholar
- Winterwerp, J., & Giardino, A. (2012). Assessment of increasing freshwater input on salinity and sedimentation in the Gorai river system. Report. Netherland: Deltares.Google Scholar