Ollie Wing

Flooding is Not Like Filling a Bath Estimates of flood risks can be strongly biased by bathtub hazard modeling Physics-based modeling reduces flood risk bias compared to bathtub modeling and is now feasible globally Short-format, ...

Please somebody at @nature.com just read this

doi.org/10.1029/2024...

The role of climate and population change in global flood exposure and vulnerability - Nature Communications This study explores how climate change and population growth shape flood exposure. By 2100, exposure could rise from 1.6 to 1.9 billion people, driven 21% by climate change and 77% by population growt...

@nature.com continue to have MDPI-level editorial scrutiny

www.nature.com/articles/s41...

Had a chat with @leeharris.bsky.social about what’s driving high UK insurance payouts 👇

There may have been some coastal events, I can’t remember. AFAIK the event models were only forced with gauged river discharge so have basically nothing to say about surge events.

Simulating historical flood events at the continental scale: observational validation of a large-scale hydrodynamic model Abstract. Continental–global-scale flood hazard models simulate design floods, i.e. theoretical flood events of a given probability. Since they output phenomena unobservable in reality, large-scale mo...

They were modelled directly using river gauges. Seemed to do an ok job all things considered (published here: nhess.copernicus.org/articles/21/...), but the sample size is *way* too small (not to mention the quality too inadequate) to give property-level true negatives

If that is solely based on the ~100? flood events shoved through the model back in 2018 then… just lol

Depends on the context. It doesn't follow that new / 'good' models simulate larger flood extents than old / 'bad' ones.

Thank you for writing my epitaph @bloomberg.com

www.bloomberg.com/news/newslet...

Nothing public as far as I can tell – I was emailed some NaFRA2 docs

National assessment of flood and coastal erosion risk in England 2024

2m resolution national flood maps with no river channels? Who reviews this stuff?

www.gov.uk/government/p...

Developing a Fluvial and Pluvial Stochastic Flood Model of Southeast Asia Global hydrological models can be used to drive a large-scale stochastic flood inundation model in Southeast Asia A reanalysis-based stochastic flood model generates realistic flood events The c...

Right! General idea is we’ll have “enough” events with a SMILE or two, and let the ML do the work at making the event magnitudes useable. All very much a WIP though. But avoiding the smorgasbord of choices in a Heffernan & Tawn type approach (eg doi.org/10.1029/2023...) would be nice!

Lastly, I had some fun arguing we should chuck the bathtub out with the bathwater (but keep the baby). Keep your HANDs to yourself!

Paper on this out recently with Brett Sanders & Paul Bates: doi.org/10.1029/2024...

Will do my best to fend off any whataboutery in the replies.

Seb Moraga on using a diffusion model to downscale a SMILE (yes, I love the acronym and no, I won't explain it)

Stochastic event sets from downscaled climate models? Yes please. So long & fuck you to arbitrary event definitions in statistical models.

#SWOT really is the real deal. Steve Chuter here showing how we can have real rather than made-up bathymetry for unsurveyed rivers.

A part of me is sad when something moves from parameterization to resolution. See you later 2y conveyance assumption. You made calibrating flow biases a lot easier 😔

On a more serious note, Chris Lucas showed us how FathomDEM is even better than FABDEM thanks to using vision transformers rather than random forest regression. It's quantitatively the best global DEM out there ... hold onto your hats for the paper (if the reviewers agree).

Also had the pleasure of meeting a #FABDEM superfan. He claimed to be the no 1 fan of FABDEM. I asked him to prove it, and he said he would do literally anything & was prepared for it to get weird. James: I have some ideas - call me.

iopscience.iop.org/article/10.1...

I'll start with my fav: Yasuo Nihei (Tokyo University of Science) chucking a daihatsu down a flume to see what would happen. I love science!

Might as well do an #AGU24 round-up now, since the clouds didn't yet clear for me while I was in DC. What a week! 🧵

They've really sharpened my view of what good-faith actors in the climate risk industrial complex should try to achieve: treat models as metaphors, be transparent about value judgements, present results with humility, and make decisions which are robust to uncertainty - not paralyzed by it.

Here's some books I've read this year on climate / risk / models / uncertainty / decision-making. I very much recommend each of them.

Thank you! Oh, man- gutted I missed out on the spicy bathtub discourse. Can we do it all over again?

Finally moved out of that toxic place; this feels more like home. Where are my old pals at? Let's talk flood risk, cat models, climate change, chaos, uncertainty, monetizing false precision & the (ab)use of models!