How a rainfall simulator saves millions of lives. Get exclusive NordVPN deal here ➵ https://NordVPN.com/veritasium. It’s risk free with Nord’s 30 day money-back guarantee! Special thanks to our Patreon supporters! Join this list to help us keep our videos free, forever: https://ve42.co/PatreonDEB If you’re looking for a molecular modeling kit, try Snatoms – a kit I invented where the atoms snap together magnetically – null ▀▀▀ Huge thanks to Okouchi-San and Dr. Sakai and everyone at NIED and the Large Scale Rainfall Simulator for their time, expertise and access to this amazing facility. A big thank you to Prof. Olga Mavrouli and Prof. Bill Schulz for their invaluable expertise on the mechanisms of landslides. ▀▀▀ References: Ulbrich, C. W. (1983). Natural variations in the analytical form of the raindrop size distribution. Journal of climate and applied meteorology, 1764-1775. – https://ve42.co/Ulbrich83 Van Boxel, J. H. (1997, November). Numerical model for the fall speed of rain drops in a rain fall simulator. In Workshop on wind and water erosion (Vol. 5, pp. 77-85). – https://ve42.co/Boxel87 Canuti, P., Focardi, P., & Garzonio, C. (1985). Correlation between rainfall and landslides. Bulletin of Engineering Geology & the Environment, 32(1). Tsaparas, I., Rahardjo, H., Toll, D. G., & Leong, E. C. (2002). Controlling parameters for rainfall-induced landslides. Computers and geotechnics, 29(1), 1-27. – https://ve42.co/Tsaparas2002 Nakamura, H., & Oosawa, M. (2021, March). Effects of the underground discharge channel/reservoir for small urban rivers in the Tokyo area. In IOP Conference Series: Earth and Environmental Science (Vol. 703, No. 1, p. 012029). IOP Publishing. – https://ve42.co/Nakamura21 Guthrie, R. H., & Evans, S. G. (2004). Magnitude and frequency of landslides triggered by a storm event, Loughborough Inlet, British Columbia. Natural Hazards and Earth System Sciences, 4(3), 475-483. – https://ve42.co/Guthrie2004 Images & Video: Miyako, Iwate Tsunami via ANNnewsCH - https://ve42.co/Miyako2011 Mount Onake Volcano via BBC News - https://ve42.co/BBCOnake Typhoon Jebi via Al Jazeera - https://ve42.co/TyphoonJebi East Asia Typhoons via CBC News - https://ve42.co/TyphoonCBC Atami Landslide via The Quint - https://ve42.co/Atami2021 Atami Landslide via news.com.au - https://ve42.co/2ndAtami2021 Sendai Earthquake via ANNnewsCH - https://ve42.co/SendaiQuake Nagasaki Mudslide via The Telegrap - https://ve42.co/NagasakiMudslide Wajima Landslide via Guardian News - https://ve42.co/WajimaLandslide Drone Rainfall Test via AIZAWAchan - https://ve42.co/DroneRain Car Rainfall Test via TIER IV - https://ve42.co/CarRainTest Rainfall Simulator via NIED - https://ve42.co/RainfallSim1 External Footage of Simulator via NIED - https://ve42.co/RainfallSim2 Landslide Simulations via NIED - https://ve42.co/RainfallSim3 Typhoon Prapiroon via Force Thirteen - https://ve42.co/TyphoonPrapiroon Yanohigashi Floods via CNA - https://ve42.co/YanohigashiFloods Japan Floods via The Telegraph - https://ve42.co/TelegraphFlood Japan Floods via euronew - https://ve42.co/EuroNewsFlood Typhoon Hagibis via Guardian News - https://ve42.co/TyphoonHagibis Typhoon Hagibis via SCMP - https://ve42.co/TyphoonHagibisSCMP Satellite Imagery of Hagibis via Force Thirteen - https://ve42.co/HagibisSatellite Tokyo Flood Control System via NikkeiAsia.com - https://ve42.co/FloodControl Landslides Footage via Underworld - https://ve42.co/MonsterLandslides Norway Landslide via ABC7 - https://ve42.co/NorwayLandslide Planet Destruction via BBC - https://ve42.co/BBCDestruction B.C. Climate Change Danger via CBC News - https://ve42.co/BCClimateChange Canada’s Logging Roads via CBC News - https://ve42.co/CBCLogging ▀▀▀ Special thanks to our Patreon supporters: Chris Harper, Max Paladino, Balkrishna Heroor, Adam Foreman, Orlando Bassotto, Tj Steyn, meg noah, KeyWestr, TTST, John H. Austin, Jr., john kiehl, Anton Ragin, Diffbot, Gnare, Dave Kircher, Burt Humburg, Blake Byers, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Josh Hibschman, Juan Benet, David Johnston, Ubiquity Ventures, Richard Sundvall, Lee Redden, Stephen Wilcox, Marinus Kuivenhoven, Michael Krugman, Sam Lutfi ▀▀▀ Directed by Petr Lebedev Written by Petr Lebedev Edited by Peter Nelson Additional Research by Gregor Čavlović Animated by Fabio Albertelli Illustrations by Jakub Misiek Filmed by Petr Lebedev, Emily Zhang, Derek Muller Produced by Petr Lebedev, Han Evans and Gregor Čavlović Thumbnail by Peter Sheppard Additional video/photos supplied by Getty Images Music from Epidemic Sound