12 December, 2021
An article by researchers from the Institute of Earth Sciences was recently published in Earth’s Future journal. The study shows that heavy precipitation events, the kind of events which contribute the most to water resources but has the potential to cause flash floods and urban flooding, will get drier in the future because of the impact of global warming. In this work the researchers used a regional weather model, similar to models used in day-to-day weather forecasting, which enables identifying and quantifying the changes expected in rainfall patterns. Using the model, a large collection of historic storms was simulated in pairs: (a) forcing historic climate conditions for the end of the 20th century, and (b) the same storms placed in a “business as usual” emission scenario for the end of the 21st century. Results of these simulations show that future storms are expected to become more “concentrated”: rainfall will have a higher intensity, focused over a much smaller area and on a shorter period. The contracted rainfall area is the main cause for the drying of future storms and can possibly cause a major decline in water resources. This decline requires decision makers to address changes in rainfall patterns in present, to avoid future crises in water supply. The effect of changes in rainfall patterns on flash floods is currently in research.