Southern Botswana and eastern South Africa faced severe flooding due to heavy rains from February 16-20, claiming 31 lives and affecting 5,500 people. A study by the World Weather Attribution revealed that such events are more likely due to human-induced climate change. Urgent infrastructure upgrades, including drainage systems, are necessary to cope with the impacts of climate change and urbanization.
From February 16 to 20, southern Botswana and eastern South Africa experienced exceptionally heavy rainfall, resulting in significant flooding and the tragic loss of at least 31 lives. In Botswana alone, the government reported that approximately 5,500 individuals were affected, with more than 2,000 people evacuated due to the severe conditions.
A recent rapid assessment conducted by the World Weather Attribution (WWA), which comprises international climate scientists, revealed that such extreme precipitation events are increasingly likely due to climate change driven by human activities. Historical weather data from the region indicates a rising trend in intense five-day rainfall occurrences over the past several decades.
The researchers assessed that the severity of similar rainfall events has intensified by approximately 60% in today’s climate, which has risen by an average of 1.3° Celsius since preindustrial times, a period preceding the extensive reliance on fossil fuels. However, the study noted the difficulty in precisely measuring how much this recent extreme event can be attributed to climate change, as the utilized climate models yielded inconsistent outcomes.
Ben Clarke, a co-author of the study and a researcher at Imperial College London, remarked, “We haven’t been able to quantify the effect, but as the world is warming, we are seeing more extreme rainfall events like this one.” Joyce Kimutai, another climate scientist at Imperial College, emphasized that a warming climate will retain more moisture, leading to increased instances of intense rainfall that can overwhelm existing drainage systems amid rapid urban development.
Piet Kenabatho, also a co-author and a professor at the University of Botswana, stressed the need for Gaborone’s infrastructure to become flood-resilient. He suggested that implementing simple nature-based solutions, such as enhancing green areas, could effectively absorb excess water during flood conditions. He noted that most green spaces in Gaborone have been converted into urban developments.
Yet, Kenabatho asserted that these methods alone are insufficient; there is a pressing need to upgrade the outdated stormwater drainage systems to effectively manage floodwaters. He suggested, “Decisions will have to be made as to where some of these waters could be stored.” Additionally, he cited managed aquifer recharge schemes employed by several African nations as potential strategies for channeling stormwater into underground reservoirs.
The recent flooding in Botswana is a stark illustration of the escalating impacts of climate change and rapid urbanization. Acknowledging the increasing frequency and intensity of extreme weather events, experts advocate for comprehensive infrastructure improvements and nature-based solutions in cities like Gaborone. Expanding and updating drainage systems, alongside enhancing green spaces, are crucial steps in mitigating future flood risks and ensuring community resilience.
Original Source: news.mongabay.com
