Saturday, 18 January 2020

Areas affected by sea level rise scenarios

Local Community Engagement 1234567891011, & 12

So far we've looked at sea level rise, timing, temperature regime and risk of flooding from land and from sea. These scenarios were developed using open data from Ordnance Survey and Climate Central for elevation models, UK Met Office for temperature and DEFRA for flooding. This was also put in a time and IPCC scenario context from scientific publications.

The second most important thing  for East Anglia Fenlands residents after the timing of such scenarios, is the actual areas affected by them. Having collected all the underpinning information, it was a matter of overlaying climate data with settlement data: infrastructure was posted in Part 2  from OS Open Zoomstack, and settlements were posted in Part 6 as a local Wikimedia gazetteer.


So here is this map updated with the settlements affected by current sea level and sea level rises of 0.5 and 2 m. As mentioned earlier, so much of the Fenlands is at or below sea level, that constant drainage is in place and settlements at sea level are at risk. Also discussed on last post,  a 0.5 m. sea level rise is a moderate risk scenario by mid-century, and 2 m. is a low risk scenario by end-century.

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This information is tabulated by settlements: The list of 70 Civil Parishes affected is posted here.

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By area shows Cambridgeshire align on Ordnance Survey data with Fenlands data posted before.

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Here is the impact of increased inundation from sea level rise on Cambridgeshire settlements:
  • mid-century consensus and models put sea level rise at 0.5 m. and temperature anomalies at 3°C in a moderate emissions scenario, while end-century estimates are 2 m. and 9°C in the same scenario
  • separate calculations point to a 84% increase in land submergence from sea level rise, in other words almost double the land would become un-arable in East Anglia considered to be England’s breadbasket 
    • this aligns with a prior post, stating that 2 m. sea level rise would double inundated lands to 25%
  • the impact on population is also dramatic at at almost half the population and a third of the settlements