Thursday, 3 October 2019

Local community engagement, Part 5

Part 1 introduced this project to engage local residents in villages north of Cambridge UK. Part 2 elaborated on some resources available and communication via Story Maps. Part 3 looked at three more resources, introduced an open call and closed with an Elevator Pitch. Part 4 looked at community engagement's key differentiator, to search for local info your way, not the search engines'. Let's round this off with our own gazetteer, and then touch on issues around sea level rise maps.

Wikipedia Gazetteer

With my cottenham.info partner Terry Jackso, we completed a Cambridgeshire gazetteer from Wikipedia data! Click on View larger map  and select any town to pop up a full suite of associated information...




Cottenham2020 are a social enterprise keen on linking villagers and businesses for the better good. The context for this is climate change, and local environmental groups such as SusCott are among our partners. The neighbouring village of Histon&Impington just declared a climate emergency. Sea level rise maps are thus part&parcel of the environmental hazard assessment... but we have a surprise!

A tale of two sea level rise models

[Update: submitted the coastal inundation map at bottom, drawn up with ArcGIS water-colour style, as a map and art version to 2020 GeoHipster Calendar competition]

Part of the climate change risk&mitigation efforts revolve around coastal inundation. I first mentioned this almost a decade ago , when I highlighted flood.firetree.net sea level rise map based on NASA SRTM data. A more recent spectacular example on the same data is shown here.



I could not, however, source the original NASA data - an issue around openness and web services discussed five years ago - but I did find a version of it on Esri's Online platform. Toggle on the  WWF / NASA 4 and 11 m. sea level rise below, and see half of Cambridgeshire inundated!



When I was doing Arctic sea ice maps, however, I found NGDC-based CReSIS sea level maps. Desktop mapping showed me a far more conservative coastal inundation of East Anglia: measured from 1 to 6 m contrasts with the 4 and 11 m above. Luck would have it that @kennethfield  I follow on twitter already posted the 1 and 5 m global sea level rise. Toggle those two on in the map above, and you'll only see the north tip of Cambridgeshire inundated!

Note: both Firetree and CReSIS maps were created in 2006 and 2005 respectively, before this became a hot topic, unlike the Risk Zone Map very much in the news evidenced here.

This highlights the issues in modelling. Do consult the sources in my East Anglia sea level rise map. On the NASA side, incremental sea levels are intersected with SRTM topographic data to derive inundation zones (any SRTM data below incremental sea levels is marked blue as under water, any above are left clear as above water). On the NGDC side a two-step raster modeling procedure run atop GLOBE and ETOPO2 elevation data models flooding scenarios.

Posting on flood data interpretation a couple of years ago will show how complex an area this is, like anything is around climate change written up on Medium here.