The Grand Challengers Podcast Episode #40

Studying the extremes – “when it rains, it floods”, and “just add water” when “the heat is on”

Guest: João P. Leitão

March 11th, 2025

Episode Teaser

Introduction

“… I’m not a person of living in the extremes, but I like to study the extremes …”

João Paulo Leitão is Senior Researcher at the Swiss Federal Insitute of Aquatic Science & Technology (Eawag), Professor at ETH Zurich and, the first guest of The Grand Challengers podcast. João is active in the areas of urban flood risk, urban water asset management, GIS, data-driven and machine learning models. Together with his research group, he has been leveraging new and emerging data sources to develop knowledge, tools to tackle the challenges of too much as well as too little water, emphasising its central role in helping our cities to combat the impacts of climate change and an uncertain future.

On today’s show, João returns to the show for a Part 2, where we reflect not only on our memories of the show’s first episode, but also discuss his ongoing work with his team in the fields of urban heat mitigation, urban drainage asset management, including blue-green infrastructures, data scarcity and data-driven models. We also hear an update on where João is heading with his research on the extremes in future and what this may look like in the changing global landscape.

Biography

João Paulo Leitão is a Senior Scientist at the Department of Urban Water Management in the Swiss Federal Institute of Aquatic Science and Technology (Eawag) and Adjunct Professor at ETH Zurich. He studied Environmental Engineering at the Technical University of Lisbon (2001) and obtained a Master of Science degree in Geographic Information Systems (2004) from the same University. After a couple of years as Research Assistant at the Technical University of Lisbon, investigating spatial analysis methods, he moved to Imperial College London for a PhD in Civil and Environmental Engineering focusing on Enhancing elevation models for advanced urban flood modelling (2009). After his PhD, João moved back to Lisbon to work as Postdoctoral fellow (2010-2013) at the Portuguese Civil Engineering Laboratory (LNEC); there he developed new methods and coordinated projects aiming to assess the performance and the risks associated with urban water systems, with a particular focus on pluvial floods. In 2013 João joined Eawag where he established himself as Group Leader on Urban Flood Risk. Since 2018, he is also lecturing Infrastructure Systems in Urban Water Management at ETH Zurich.

João has more than 10 years of experience in urban flood risk assessment and urban water asset management, and has published over 60 ISI-cited articles since 2005. He specialises in exploring novel data sources, such as images and videos, to estimate flood data to support flood risk management in urban areas. In particular, he has been developing new methods to extract flood depth and velocity from videos and images obtained from social media and surveillance cameras. He has also been pioneering the development of data-driven two-dimensional flood prediction models that can be used to inform rescue services during urban pluvial events and help protecting citizens and assets threatened by these events.

During João’s scientific career, he has been the recipient of a few fellowships and grants. He serves frequently as reviewer for various journals and of scientific proposals. Currently, João is Associate Editor of the Urban Water Journal and Chair of the International Working Group on Data and Models (IWGDM) of the IWA/IAHR Joint Committee on Urban Drainage (JCUD).

Resources Related to the Episode

  • Revisit the very first episode of the podcast!
  • Bacalhau Recipes can be found all over the web, here is one with chickpeas and a baked one if you have your own preferred Bacalhau recipe, feel free to share it on our LinkedIn group!
  • Portuguese Wine – here is the selection of Segredos de Sao Miguel that we enjoyed over new years
  • Portugal and Cork [VisitPortugal] and more about the Cork Tree (Quercus suber)
  • On Joao’s promotion to Adjunct Professor at ETH Zurich
  • Rainfall:
    • More on Nadav Peleg from the University of Lausanne
    • Peleg, N., Wright, D.B., Fowler, H.J., Leitão, J.P., Sharma, A. and Marra, F., 2024. A simple and robust approach for adapting design storms to assess climate-induced changes in flash flood hazard. Advances in Water Resources, 193, p.104823. [Open Access Link]
    • Peleg, N., Ban, N., Gibson, M.J., Chen, A.S., Paschalis, A., Burlando, P. and Leitão, J.P., 2022. Mapping storm spatial profiles for flood impact assessments. Advances in Water Resources, 166, p.104258. [Open Access Link]
    • Cache, T., Gomez, M.S., Beucler, T., Blagojevic, J., Leitao, J.P. and Peleg, N., 2024. Enhancing generalizability of data-driven urban flood models by incorporating contextual information. Hydrology and Earth System Sciences, 28(24), pp.5443-5458. [Open Access Link]
  • Model Complexity vs. Data Quality & Resolution:
    • More about Fabrizia Fappiano [LinkedIn]
    • Fappiano, F., Maurer, M. and Leitão, J.P., 2024. Coupling sewers to the surface: Systematic approaches to correcting data discrepancies for 1D-2D drainage modelling. Journal of Hydrology, 645, p.132239. [Open Access Link]
  • Joao references his discussion with Peter Vanrolleghem, who has been on the show (check out Episode 5)
  • I reference my PhD supervisor, Ana Deletic, who has also been on the show (checkout Episode 9)
  • Urban Drainage Asset Management:
    • More on Prabhat Joshi [LinkedIn] – for his work on asset management of blue-green infrastructures, watch this space.
    • Langeveld, J.G., Cherqui, F., Tscheikner-Gratl, F., Muthanna, T.M., Juarez, M.F.D., Leitão, J.P., Roghani, B., Kerres, K., do Céu Almeida, M., Werey, C. and Rulleau, B., 2022. Asset management for blue-green infrastructures: a scoping review. Blue-Green Systems, 4(2), pp.272-290. [Open Access Link]
  • The Co-UDlabs Project and more on Jörg Rieckermann
  • The Heat Down Project:
    • Details on the project [Eawag’s Website] [petermbach.com]
    • Part of the project was covered on Episode 39 with Lucas Gobatti
    • More on Jixuan Chen [LinkedIn]
    • The literature review: Probst, N., Bach, P.M., Cook, L.M., Maurer, M. and Leitão, J.P., 2022. Blue Green Systems for urban heat mitigation: mechanisms, effectiveness and research directions. Blue-Green Systems, 4(2), pp.348-376. [Open Access Link]
    • Chen, J., Bach, P.M., Nice, K.A. and Leitão, J.P., 2024. Investigating the efficacy of a fast urban climate model for spatial planning of green and blue spaces for heat mitigation. Science of the Total Environment, 955, p.176925. [Open Access Link]
    • Gobatti, L., Bach, P.M., Scheidegger, A. and Leitão, J.P., 2023. Using satellite imagery to investigate Blue-Green Infrastructure establishment time for urban cooling. Sustainable Cities and Society, 97, p.104768. [Open Access Link]
    • What is Uchimizu?
  • Parkinson’s Law – work fills the space of time allocated to it
  • Joao’s Paper on Landslides: Devanand, V.B., Mubeen, A., Vojinovic, Z., Sanchez Torres, A., Paliaga, G., Abdullah, A.F., Leitão, J.P., Manojlovic, N. and Fröhle, P., 2023. Innovative methods for mapping the suitability of nature-based solutions for landslide risk reduction. Land, 12(7), p.1357. [Open Access Link]
  • How to say Cheers! in 10 languages or 17 different languages and the promised German puns and Portuguese puns

Episode Chapters

(Chapters are embedded in the episode for quick access, click this to expand and view all chapters and time stamps)
  • 0:00 Intro
  • 2:04 Guest Intro and Reflections on the podcast
  • 4:45 The return of salted cod (Bacalhau)
  • 7:02 Portuguese Wine and Cork
  • 9:23 A curious case of inheritance
  • 13:30 Getting into the science
  • 14:58 Updates in the world of flood models
  • 16:42 Rainfall intensities & flood volumes
  • 19:12 Balancing model complexity and insight
  • 22:54 Joao’s preferred term for BGI
  • 24:29 Urban drainage asset management
  • 29:03 Encouraging more data exchange and joint learning
  • 31:05 Speaking a different language in disciplines
  • 33:11 Leveraging time zones for research productivity
  • 37:34 Beginning our journey on urban heat together
  • 42:12 Uchimizu
  • 49:03 Is GIS becoming more relevant?
  • 52:21 The next stage of Joao’s research
  • 54:32 Q&A Start
  • 54:59 If you had a magic wand?
  • 58:29 What do you define as innovation?
  • 1:00:51 Favourite childhood memory
  • 1:03:58 What would you like to be remembered for?
  • 1:04:53 Easter Egg: A not German joke
  • 1:06:57 Final Message
  • 1:07:57 Outro

Connect with João P. Leitão

Related Episodes

Episode #1 – João P. Leitão
Engineers never say never and never say always – a new take on flood models
(Related Topics: engineering; blue-green infrastructure; data)
Episode #16 – Mattheos Santamouris
A ‘hot’ topic for ‘cooler’ cities – high performance architecture to combat urban overheating
(Related Topics: urban heat; climate change; heat mitigation)
Episode #38 – Patricia Cuervo Uría
The human side of planning and flood risk in London – the challenge of embedding history into policy
(Related Topics: planning; flood risk; extreme events)
Episode #39 – Lucas Gobatti
Spinoza, science, spirituality – confronting ‘displacements’ in planning urban nature, climate and heat
(Related Topics: urban heat; blue-green infrastructure)

Credits