How Climate Change Can Adversely Affect the Coastal Zone
Tharani Gopalakrishnan
by Tharani Gopalakrishnan, Lalit Kumar, Journal of Coastal Research, J. of Coastal Research, 36(5):951-960 (2020). May 26, 2020
Gopalakrishnan, T. and Kumar, L., 2020. Potential impacts of sea-level rise upon the Jaffna Peninsula, Sri Lanka: How climate change can adversely affect the coastal zone. Journal of Coastal Research, 36(5), 951–960. Coconut Creek (Florida), ISSN 0749-0208.
Sea-level rise (SLR) is anticipated to be one of the most crucial factors putting pressure on the livelihood of human life in the 21st century. The Jaffna Peninsula, located at the northern tip of Sri Lanka, is no exception. This area lies entirely within 10 km of the coast and has an almost flat topography with a maximum elevation of 15 m above mean sea level (a.s.l.), whereas 50% of the total land area is less than 2 m a.s.l., making it highly vulnerable to coastal hazards, including SLR. An attempt was made to estimate the extent of land and paddy fields area that will be potentially inundated by 2050 and 2100 on the basis of different Intergovernmental Panel on Climate Change Representative Concentration Pathway (RCP) scenarios. Across four SLR scenarios, the total land area of the Jaffna Peninsula that will be directly inundated by 2050 is 6.8–13% and by 2100 this value will rise to 10–35%. Moreover, the Jaffna Peninsula is projected to lose approximately 7193–13,595 ha of paddy fields by 2050 and 10,630–36,786 ha by 2100. Considering the uncertainty in the inundation model, the total land area that could be under risk of inundation is 46.3% and 49.1% by 2050 and 2100, respectively, under the low-end scenario (RCP2.6), and 47% and 58.5% under the high-end scenario (RCP8.5). The areas surrounding the lagoons and the adjacent islands are identified as being the most vulnerable to SLR. The scale of the anticipated inundation on land and paddy fields underscores the urgent need for action to ensure the sustainable livelihoods of the region’s population.
Coastal settlement patterns and exposure to sea-level rise in the Jaffna Peninsula
by Tharani Gopalakrishnan, Lalit Kumar & Md Kamrul Hasan, Population and Environment volume 42, pages 129–145 (June 1, 2020)
The Jaffna Peninsula of Sri Lanka showing elevation from mean sea level. The inset box shows five Indian coastal cities based on which the sea-level rise of the Jaffna Peninsula was projected
Residential density across 1 km buffer intervals of distance from the coast in the Jaffna Peninsula
Spatial distribution of residential houses in the Jaffna Peninsula across elevation
Abstract
The Jaffna Peninsula in Sri Lanka has a generally flat topography with a median elevation of 2.72 m, and thus faces a high risk from sea-level rise that has the potential to have adverse impacts on the livelihoods of coastal communities. Understanding these risks and identifying the regions that could be adversely impacted is critical for planning future settlements and developing preventative protocols where possible. The aim of this study was to analyze the exposure of coastal settlements of the Jaffna Peninsula to climate risks, particularly to sea-level rise, and to identify the areas that are likely to be impacted under different sea-level rise scenarios. Raster-based sea-level rise modeling was performed with a digital elevation model produced with topographic contours and spot heights. The spatial distribution of individual residential houses for the entire Jaffna Peninsula was obtained through manual digitization using virtual globe platforms and high-resolution satellite images, and the houses exposed to inundation under various Representative Concentration Pathways from 2025 to 2100 were identified. The results showed that a majority (55.5%) of the residential buildings in the Jaffna Peninsula are located within 3 m above sea level. Approximately 5554 (5.6%) of the houses were projected to be inundated by 2100, and this projection increased to approximately 25,074 (25.4%) under high tide scenarios. This study highlights the coastal communities with a high level of exposure to coastal inundation where adaptation planning is essential. These results provide insights for coastal managers and policy makers for future planning of new settlements and urban expansion.