The Impact of Climate Change and Urbanization on Gaborone’s Floods
Severe flooding in mid-February 2025 struck Botswana and South Africa, resulting in 31 fatalities and displacing over 5,000 individuals. The flooding, exacerbated by extreme rainfall and inadequate infrastructure, highlighted the effects of human-induced climate change. Research indicates a significant relationship between climate change and increased rainfall intensity. Strategies for resilience improvement are currently being developed.
In mid-February 2025, heavy rainfall struck southern Botswana and eastern South Africa, resulting in catastrophic flooding. This disaster claimed 31 lives, with 22 fatalities in KwaZulu-Natal and nine in Gaborone, including six children. More than 5,000 residents were displaced, and the flooding disrupted major transportation routes and government services, leaving many isolated from emergency assistance.
Researchers from multiple countries investigated the impact of human-induced climate change on the rainfall event contributing to the floods. They focused on the maximum rainfall observed over five days where the flooding was most severe, with relevant data provided by ERA5. Analysis revealed that Gaborone routinely experiences flooding during the rainy season due to urbanization and insufficient drainage systems.
The extreme rainfall event in February 2025 is considered rare, with a return period of 40 years, suggesting a 2-3% chance of occurrence annually. Even under current warming of 1.3 °C, such intense rainfall would have been significantly less likely in a colder climate, with a potential 60% increase in intensity attributable to climate change.
The investigation utilized climate models to assess historical rainfall patterns, noting considerable variability in predictions. While some models indicated increased frequency and intensity of extreme rainfall, others suggested stability or decrease. This disparity complicates the precise quantification of climate change’s impact.
With projected warming increasing to 2.6 °C later this century, most models forecast an augmentation in heavy rainfall events. This correlation supports the conclusion that human-induced climate change intensified the rainfall responsible for the floods in southern Botswana, though an exact quantification remains elusive.
As the majority of the negative impacts from the February event stemmed from urban flooding, it is evident that the existing infrastructure failed to accommodate such extremes. Roads and drainage systems were overwhelmed, impacting local health services significantly.
To enhance resilience against future flooding, initiatives are underway to improve drainage systems, regulate land use, and boost disaster preparedness. Enhancements like expanded drainage capacity, zoning reforms, and infrastructure upgrades are vital for resilience. A strategic, integrated approach that includes comprehensive hazard assessments in urban planning and robust early warning systems will be essential for coping with future extreme weather events.
The floods in Gaborone were driven by increasing extreme rainfall, exacerbated by rapid urbanisation and failing infrastructure. While human-induced climate change contributed to the severity of these rainfall events, quantifying its exact impact presents challenges due to variability in climate models. Strengthening urban infrastructure and implementing comprehensive flood resilience strategies are crucial for mitigating future risks.
Original Source: www.preventionweb.net
