Relative sea level change in the Forth and Tay Estuaries: past changes informing future trends

  • Victoria Alicia Powell

    Student thesis: Doctoral ThesisDoctor of Philosophy


    This thesis introduces new relative sea level datasets from the Forth and Tay Estuaries dating between 1900 and 2010 and uses these to analyse sea level oscillations, surge components and to influence future sea level projections. Prior to this research, relative sea levels had not been analysed across this region. These datasets were collated and corrected using renowned methods and investigated using Shennan et al.’s (2012) GIA corrections, Torrence and Compo’s (1998) Morlet wavelet transform and Graff’s (1981) sea level maxima analysis. The relative sea level data were then used to support adaptations of two sea level projection models to 2100; the UK Climate Projections 2009 (UKCP09) probabilistic model and Vermeer and Rahmstorf’s (2009) temperature-sea level relationship projections model. These models were, in turn, used to project the impact of extreme relative sea levels on local infrastructure by 2100.
    This research revealed that relative sea level in the Forth and Tay Estuaries between 1900 and 2010 rose at a rate of 0.27 to 0.56 mm a-1, which is smaller than the global average of 1.7 mm a-1 (Church and White, 2011). Tidal residuals were commonly observed to be approximately 0.4 and 0.7 m at Leith and Dundee between 2003 and 2010, whilst the highest sea level maxima across 5 ports in the region ranged between 3.27 and 4.13 m above OD. Adaptions of the UKCP09 model reduced the original projections for 2100 of between 31.3 and 35.1 cm to between 24.3 and 27.5 cm above the 1990 mean. Similarly, adaptions of the Vermeer and Rahmstorf (2009) model reduced projections from 107.5 cm to between 50.9 and 54.2 cm above the 1990 mean. These adapted projections, when added to the extreme 2100 sea level calculations, suggests that the highest extreme sea level by 2100 could reach the present day quayside heights at selected locations in the Forth and Tay Estuaries. The approach and results are replicable across other regions, thereby refining projections made by previous authors.
    Date of Award2012
    Original languageEnglish
    SponsorsForth Ports Ltd
    SupervisorRobert Duck (Supervisor) & Derek McGlashan (Supervisor)

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