Sea level change around the Philippines

Transcription

1 Sea level Sea level around the Philippines Institute of Environmental Science for Social Change (ESSC) Conference on Internal Migration and Displacement Davao City, Philippines 20 May 2012 Regional

2 How are sea levels changing around the Philippines? Global, regional, local factors Spatial, but also temporal Effect of rising sea level on extreme events Risks to ecological services and the human ecosystem Sea level Regional

3 Main factors causing global increase thermal expansion melting of small glaciers ice loss from the Greenland and West Antarctic Ice Sheets Sea level Regional

4 c s expansion, glaciers and ice caps, and modeled ice - sheet contributions and is for a sea - of cm in 2095 (the magenta bar). This contribution is similar to, but slightly smaller than, the equivalent range from the TAR (the light shaded Projected range of mean sea 1 Global mean sea level (m) Eustatic rate: 3.1(±0.4)mm/yr ( ) Larger values cannot be excluded Additional contributions from potential ice sheet dynamic processes Model projections Year Sea level Regional

5 Regional 2 Sea level ai 90 Rate around the Philippines: 5.8 (±0.6)mm/yr Regional b Sea level (mm year 1) Figure 3 (a) Map of spatial trend patterns of observed sea level between January 1993 and December (b) Same as (a) but a uniform global mean trend of 3.4 mm year 1 has been removed.

6 Regional Some factors affecting regional s land water storage gravitational attraction of water to land or ice mass vertical land movement (subsidence or uplift) Sea level Regional

7 Increase in sea levels by Not relative sea level Sea level Regional

8 Coastal vulnerability index 4 mean sea level trend mean significant wave height mean tidal range coastal slope (coastal erodibility) (rate of erosion) Sea level Regional

9 Coastal vulnerability index Physical factors, not including human vulnerability Sea level Regional

10 ENSO and the summer monsoon (JAS) high sea levels match high MEI values Sea level Regional min = 27.1; max = 36.2 JAS mean SSHA [mm] log scale

11 ENSO and the winter monsoon (DJF) high anomalies when MEI values switch extremes Sea level Regional min = 27.7; max = 22.3 DJF mean SSHA [mm] log scale

12 Frequency distribution of water levels, median 2m Sea level Tidal levels at Davao ( ) Regional [meters] Frequency of hourly events (x1000)

13 Effect of a 20-cm increase in mean sea level Increase in frequency of high water levels Sea level (to datum) [m] Frequency analysis of annual maximum series for Davao tide gauge, Observations Fitted distribution % confidence interval 20cm increase in sea level 1996 maximum water level yr 1.05 yr 1.11 yr 1.25 yr 1.50 yr 2.00 yr 3.00 yr 5 yr 10 yr 20 yr 50 yr 100 yr 200 yr 500 yr 1000 yr Sea level Regional Exceedance probability

14 5 Coastal flooding (surge and backwater effect) Land loss (wetlands, erosion) Freshwater aquifer contamination Soil degradation from salinization Sea level Regional

15 Risk to human ecosystems Disruption of lives and livelihood Displacement of property and industries Destruction of resources that provide ecological services Destabilization of resource tenure Sea level Regional

16 Global requiring local action Spatial and temporal Issues other than simply water levels Risks to both natural and human ecosystems Sea level Regional

17 References 1 Church, J.A. et al. (2010) in Understanding Sea-Level Rise and Variability edited by J. A. Church et al., pp Cazenave, A. and W. Llovel (2010) Annu. Rev. Mar. Sci. 2, Clavano, W. R., Ecojesuit (Programs and Projects), 30 April Thieler, E. R. and E. S. Klose ( ) USGS Open File Reports, usgs.gov/project-pages/cvi/. 5 Nicholls, R. J. et al. (2007) in IPCC WGII AR4, edited by M. L. Parry et al., pp Sea level Regional

18 Resources Mean significant wave height: Young, I. R. et al. (2011) Science 332, Topography & bathymetry: S2004 v14.1, 22 Jun Vector shoreline: GSHHS v1.5, 14 Sep 2004 (updated v2.2.0, Jul 2011). Tidal range: FES2004, 22 Mar Mean sea level trends (Oct 1992 Dec 2011): AVISO, GIA model: Peltier, W. R. (2004) Ann. Rev. Earth Planet. Sci. 32, Philippine human exposure and vulnerability indices: Manila Observatory (2005), Geohazard maps: DENR MGB (2011), Sea level Regional

19 University of Arizona Brigham Young University EPaM, Commission universitaire pour le Développement (Belgium) M. Mulligan, King s College London F. P. Siringan, Marine Science Institute, U.P. Diliman I. Young, Australian National University S. Zieger, Swinburne University of Technology P. Woodworth, U.K. National Oceanography Centre Natural Resources Canada Library Sea level Regional

20 such as around the southern North Sea, and major flood disasters remain possible in any coastal region. Under the SRES climate and socioeconomic scenarios the Sea level Number of people at risk from sea 6 6 igure Nicholls, 2.9 The regions R. J. (2010) most in vulnerable Understanding to coastal Sea-Level Rise time and of Variability, 45 cm (note: edited the African by J. A. coastline Church et comprises al., pp. three ooding, based on an illustrative scenario for the 2080s, regions ). (Adapted from Nicholls et al ) ssuming a middle estimate of global sea - by that Regional

21 [meters] Predicted tide for Davao, January No weather effects Example of semidiurnal tidal type (Davao tide gauge) with moon phases 1 First Quarter Full Moon Last Quarter New Moon Time (days in January 1984) Sea level Regional

22 Global MSL and MEI values 7 Sea level Regional GMSL (60-day smoothed, detrended, seasonal signals removed) Multivariate ENSO Index 7 CU Sea Level Research Group (2011),