Quantifying and Projecting Relative Sea-Level Rise At The Regional Scale: The Bangladesh Sea-Level Project (BanD-AID)

Tuesday, 16 December 2014
C.K. Shum1, Chungyen Kuo2, Junyi Guo3, Kun Shang3, Kuo-Hsin Tseng4, Junkun Wan5, Stephane Calmant6, Valérie Ballu7, Pierre Valty8, Juergen Kusche9, Faisal Hossain10, Zahirul Haque Khan11, Roelof Rietbroek12 and Bernd Uebbing12, (1)Ohio State University, School of Earth Sciences, Columbus, OH, United States, (2)NCKU National Cheng Kung University, Tainan, Taiwan, (3)Ohio State University Main Campus, Division of Geodetic Science, School of Earth Sciences, Columbus, OH, United States, (4)Ohio State University Main Campus, Columbus, OH, United States, (5)The Ohio State University, Columbus, OH, United States, (6)IRD, Toulouse Cedex 09, France, (7)LIENSs/Université La Rochelle, La Rochelle, France, (8)IGN Institut National de l'Information Géographique et Forestière, Paris Cedex 13, France, (9)University of Bonn, Institute of Geodesy and Geoinformation, Bonn, Germany, (10)University of Washington Seattle Campus, Civil and Environmental Engineering, Seattle, WA, United States, (11)Institute of Water Modelling, Dhaka, Bangladesh, (12)University of Bonn, Bonn, Germany
The potential for accelerated sea-level rise under anthropogenic warming is a significant societal problem, in particular in world’s coastal deltaic regions where about half of the world’s population resides. Quantifying geophysical sources of sea-level rise with the goal of improved projection at local scales remains a complex and challenging interdisciplinary research problem. These processes include ice-sheet/glacier ablations, steric sea-level, solid Earth uplift or subsidence due to GIA, tectonics, sediment loading or anthropogenic causes, hydrologic imbalance, and human processes including water retention in reservoirs and aquifer extraction. The 2013 IPCC AR5 concluded that the observed and explained geophysical causes of global geocentric sea-level rise, 1993–2010, is closer towards closure. However, the discrepancy reveals that circa 1.337.5% of the observed sea-level rise remains unexplained. This relatively large discrepancy is primarily attributable to the wide range of estimates of respective contributions of Greenland and Antarctic ice-sheets and mountain/peripheral glaciers to sea-level rise. Understanding and quantifying the natural and anthropogenic processes governing solid Earth (land, islands and sea-floor) uplift or subsidence at the regional and local scales remain elusive to enable addressing coastal vulnerability due to relative sea-level rise hazards, such as the Bangladesh Delta. This study focuses on addressing coastal vulnerability of Bangladesh, a Belmont Forum/IGFA project, BanD-AID (http://Belmont-SeaLevel.org). Sea-level rise, along with tectonic, sediment load and groundwater extraction induced land uplift/subsidence, have exacerbated Bangladesh’s coastal vulnerability, affecting 150 million people in one of the world’s most densely populated regions. Here we present preliminary results using space geodetic observations, including satellite radar and laser altimetry, GRACE gravity, tide gauge, hydrographic, and GPS/InSAR observed land subsidence, and via fingerprint sea-level adjustment and reconstructed sea-level approaches, for improved quantification of major contributions to, and the projection of relative sea-level rise at the Bangladesh delta, towards addressing its coastal vulnerability and sustainability.