Monday 7 September 2020

Sea level rise web map, poster and pirate map

[ Update 3: action in Update 1 resulted in Trinity Hall declaring divestment... hurray!
Update 2: the next post rounds this up with a Story Map that includes flood risk
Update 1: here is a video of the action mentioned below, re: colleges divest from oil ]

An Extinction Rebellion Cambridge action, demanding colleges divest from oil investment, led to a simple yet arresting idea: map the level below 12 m. sea level rise each college would be under, if climate change we left unabated, as a means to help convince them of the consequences of climate inaction., Bristol UK

Inspired by this poster, the introduction to the action's how-to manual ends with: 

Recent news, however, suggested an accelerated ice melt in the Arctic, especially the Greenland ice sheet. Together with Antarctica, it is considered the bellwether for extreme SLR [ sea level rise ] of 6 and 15 m. That had me revise the maps with an additional 12 m. level. Note however that the timing for such a SLR is still debated, the data being so new and the models in constant re-adjustment.

But simply mapping the immersion of infrastructure wraps up in one simple meme all the maps and information written up so far and listed in this status quo post

Update: here's a final scene of central Cambridge under various sea level rise scenarios.

Web map

In a nutshell, use GIS to subtract a location's current elevation from a purported current sea level + 12 m. reflecting that new SLR. Rather than post university college locations for the action above, let's post the settlements - Civil Parishes as they're called in East Anglia - for the Cambridgeshire and Peterborough Combined Authority, the focus of the current social enterprise.

Let's step through this map, shall we? Toggle legend and contents, and turn on layers in sequence, or turn each one off before the next one for more clarity:
  1. If needed select the Home button and turn off the top three layers. That gives you the settlement infrastructure, thinning out markedly northeast toward the Fens.
  2. Click on any of the dots to pop up links to pictures and pages in Wikipedia of 270 Civil Parishes assembled by social enterprise partner Terry Jackson
  3. The next layer up helps you appreciate the extent of submergence under 12 m. SLR... about half of East Anglia considered England's bread basket!
  4. The next one shows the depth under 12 m. SLR each settlement might be: notice submergence increase northeastward but not in a uniform manner.
  5. Lastly see how population increase to the southwest and submergence to the northeast, again not in a uniform manner - this is called a bivariate display.


How can a web map - however compact and easy to use - be conveyed in hustings or town hall meetings, or village hall meetings in the Fen Edge north and east of Cambridge? Taking a page again from pre-pandemic social actions, posters have proven to be very popular to convey SLR to the public at large in parks and shopping malls. So let's repeat the same in a four-panel poster:

click to enlarge (large format A0 here)

Pirate map

Inspired by Get Kids into Survey as well as John Nelson's Tattered Map Sandwich, here is a fun way to look at this serious subject: simply post submerged areas in blue liners, and those remaining above water as grassy hummocks. Posted 'naked' at first as a simple handout to tell a story, a legend was added to explain the content, and overlain as a virtual second sheet  as per pirate lore: you get either map or directions, but only both under special circumstances... apparently the source of Argh! Pirate legends!

click to enlarge (small format A4 here)

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