Tuesday, 21 January 2025

London Thames Barrier revisited

Update: see addition at bottom... thanks to our indefatigable London climate activists!

Further to Cumbria Classic revisited here and exhuming my old thesis here, I was asked to share maps of the area surrounding the Thames Barrier (Wikipedia): A group considered the necessity for a second barrier under Climate Change that increases both flooding and sea level seasonal elevations. 

I made maps & handouts here 5 yrs. ago among a DIY series here to encourage citizen science: these help address Climate  Change in a proactive way using freely available UK guv data on almost-free software from ESRI.com or free from QGIS.org (here or folders above).

The original materials were in handout form for A4 posters, presentations on computer, YouTube videos or Web maps. The latter had to be curtailed because online maintenance were too dear for personal use of Environment Agency data once cleaned-up, corrected and re-posted, even for lower Thames Valley alone. The audience was moreover the public in Town Hall or Council meetings, so reverting to broadsheet paper maps turned both portable and available no matter what the circumstances. Below is my frmr. thesis supervisor explaining So. Can. Rocky Mtns. geology on his map West of Calgary, CAN 

Whence the mountains?, pers. perm. late RA Price, centre left,
Kananaskis Country, W Canada, click to enlarge

So A0 versions were created for the Risk of Flooding from River and From Sea (RoF) from Environment Agency. Sea Level Rise Models (SLR) simply intersected elevation surfaces with Ordnance Survey topography in a GIS. Note that RoF are comprehensive flood models shown here under Open Government License. SLR are however straight geometry with no factors such as absorption, run-off or interaction with RoF, also shown under Ordnance Survey Crown Copyright detailed on the A0 maps. 

Risk of Flooding,  full A0 map here, click to enlarge

Sea Level Rise, full A0 map here, click to enlarge

Note: A0 is full-fledged c/w notes, download for 150dpi resolution meant for poster print

Update: meant for a paper in ClimateCultures, the final map is not only a hi res."vector PDF" that scales well, but it also conflated both maps - aqua Flood Risk below colour half-tone Sea Level Rise - not only to post a single map, but also to show their interplay. Here is the full A0 version.

Finally, that publication by-line is "creative conversation for the Anthropocene": Did you know I wrote a decade ago in early Anthropocene Review (here) about story maps, a multi-faceted way to reach all stakeholders? Kudos to ClimateCultures for melding Arts & Science!



An historic footnote: why did I post the cities nearest the Thames Barrier in yellow? Because it's not on Ordnance Survey's GB Basemap! Even OpenStreetMap located it without posting it here.

That's because while roads, streets, buildings, rivers etc. are on all maps, railroads aren't on all maps, and industrial facilities like factories & powerplants are not: there's an unwritten rule that military targets aren't posted; and while that definition may vary and go back to Ordnance Survey origins (here), this goes back to WWII here.

During the first Blitz, bombings in England by the Germans were called Baedeker Bombings... The Luftwaffe initially used tourist guidebooks with excellent maps called... Baedeker (Wikipedia)! British viewers may remember TV traveloguer Michael Portillo holding them like a preacher his Bible... Americans may've seen Portillo on PBS or BBC America.

1 comment:

  1. Wow, it sounds like you've been doing some amazing work on climate change and citizen science! I love how you've made maps and handouts available to help people understand the issue and take action. It's great that you're using freely available data and software to make this information accessible to everyone.

    I also appreciate your commitment to sharing knowledge with the public, even when it means adapting to changing circumstances, like the cost of online maintenance. Your broadsheet paper maps are a great solution for making this information portable and available to everyone.

    It's also lovely to see the photo of your former thesis supervisor explaining the geology of the Rocky Mountains on his map. It's clear that you have a passion for geology and sharing knowledge with others.

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