G20 RIWG Hackathon: Forecasting Informal Urban Expansion and Flood Risk 3rd to 12th September 2025
The Hackathon formed part of one of the proposed deliverables for the G20 Research and Innovation Working Group (RIWG) in 2025, namely, to implement a Demonstrator Project under the broader theme of Disaster Risk Reduction using Open Innovation (DRR- OI). The G20 RIWG Hackathon delivered accurate mapping and short‑term forecasting, which combined with flood‑hazard overlays will help plan services, target upgrades, and improve early‑warning systems.
The partners included Department of Science, Technology and Innovation, National Research Foundation (NRF), NRF SAEON, Council for Scientific and Industrial Research (CSIR), Technology Innovation Agency (TIA) and Digital Earth Africa.
The G20 RIWG Hackathon delivered accurate mapping and short‑term forecasting, combined with flood‑hazard overlays, and inform early‑warning systems: Change Detection – Identify recent growth in informal settlements, Forecast Expansion – Predict development over 1–3 years; and Risk Classification – Overlay forecasts with flood hazard maps. The hackathon used the Digital Earth Africa platform whose mission is to unlocking the promise of tomorrow from patterns of the past.
G20 RIWG made the call for the applications in July and the registrations were closed on 23 July 205 with 110 registered participants from 30 countries. The evaluation was done on 15 August 2025 with 23 countries and a total of 45 participants. The Kick off of hackahton was on 3 September 2025 and participants completed on 12th September 2025. The hackathon received submissions from 10 countries; Canada, China, Ethiopia, Japan, Malawi, Republic of Korea, Saudi Arabia, Singapore, South Africa and Turkey. The results of the hackathon were presented in the week of 17 September 2025 to 23 September 2025 at the G20 Ministerial Meeting in Pretoria, South Africa. The overall winner was Dr. Charles Takalana (South Africa), second was Singapore team and third was team AIRCAS team from China. Dr. Charles Takalana presentation was on Urban Flood & Growth Intelligence Dashboard showcasing Durban (South Africa) https://youtu.be/km0HHca_rwg, Singapore presented on flood risk assessment showcasing Maputo (Mozambique) https://youtu.be/PiIxRAXejTk and AIRCAS presented on Informal settlements expansion and flood risk in Kibera slum (Kenya) https://youtu.be/jQO6nMYtIDE.
Department of Science, Technology and Innovation thanks all partners and participants.
Mmampei Chaba (DSTI), Dr. Tshiamo Motshegwa – NRF, Dr. Nobubele Shozi – CSIR, Kenneth Mubea (DE Africa), and Teboho Seseng (TIA).
