Firefighters battle a fire at Signal Hill in Cape Town. Wildfires may occur frequently.Photo: Roger Bosch/Getty Images
The City of Cape Town's transport infrastructure, valued at R20-billion, is at high risk of coastal flooding and fires, according to new analysis.
In a paper published in Journal of the South African Society of Civil EngineersAccording to the University of Cape Town team, researchers quantified the amount of transport infrastructure at risk from severe weather and estimated the direct economic value.
“Damage to transportation infrastructure threatens access to socio-economic opportunities,” the paper said.
Transport is directly and indirectly affected by weather and climate change, says Tanya Lane-Visser from the UCT Center for Transport Research in the School of Civil Engineering, in collaboration with transport guru Marianne Vanderschulen. explain.
“Direct vulnerabilities consist of impacts on physical infrastructure and non-physical impacts on human health, behavior and decision-making,” Lane-Visser said.
Indirect vulnerabilities are caused by the transport sector's interactions with and dependencies on other critical infrastructure and social systems, such as water, electricity, information and communications, and petroleum systems.
She said quantifying the potential socio-economic impacts of climate-related disasters in the city revealed that 79.6 per cent of Capeton residents live in high-risk areas. “About 45.5% of the population lives in areas at high risk of flooding, and a further 11% will be exposed to extreme flooding.”
Coastal flooding could affect 28.9% of the population. “Employment levels are highly correlated with population levels, and severe weather can negatively impact 50% to 80% of a city's workforce.”
The analysis showed that 15.2% of the city's schools and 28.8% of health facilities were located in high-exposure areas. “Extreme weather events can therefore have a significant impact on access to health care and, to a lesser extent, educational opportunities in Cape Town,” Lane-Visser said.
climate forecast
Use geographic information systems (GIS) to overlay areas exposed to climate-related threats on a city's transportation network and infrastructure to identify and quantify the amount of infrastructure at risk I made it possible.
Four major climate-related changes are facing cities. These are a decrease in the average annual precipitation and a change in the seasonality of precipitation. Average annual temperatures will rise and maximum temperatures will rise (more hot days, more frequent and intense heat waves). Increase in average wind strength. Storms will increase in intensity and frequency, resulting in short periods of intense rainfall events. and an increase in the magnitude and duration of coastal storms. Furthermore, sea level rise will continue to occur.
The study found that the frequency of dry years in the city has already doubled, and that “Cape Town's spectacular 'day zero drought' from 2015 to 2017 has affected most Capetonians' It's still fresh in my memory.”
“The projected increase in temperatures, combined with the effects of increased wind speeds and lower humidity, will increase the fire risk for both natural (grassland) and urban fires.
“High winds and prolonged wind conditions will further exacerbate the challenges of extinguishing and extinguishing any fires that occur, ultimately impacting the potential damage that fires can cause,” the newspaper said in October 2018. He noted that 4,000 people were evacuated due to the fire and 500 people were evacuated. A week later, an informal settlement was destroyed in Capricorn Park.
Cape Town Port operations have been “adversely affected by the occurrence of strong winds, as evidenced by the closure of the port for 9.5 days in December 2019 and for four consecutive days in January 2020”, while Cape Town The highest temperature ever recorded (45.2 degrees). C) January 2022.
“This is 3 degrees Celsius above the previous maximum temperature. On that day, Cape Town was the hottest place in Africa.”
The authors cite another study that found 334 major floods occurred in the Western Cape between 1900 and 2018. Floods in June 2008 left 5,500 people homeless on the Cape Flats, followed by floods in July 2008 that affected 16,000 people. .
“The most recent major floods in Cape Town occurred in September 2023 and forced the closure of all major roads leading into Cape Town due to widespread flooding, landslides and rockfalls.
“Storms intensified by climate change have claimed at least 11 lives and forced the evacuation of around 1,000 low-lying homes. Cape Town is predicted to become drier, but changes in weather patterns in the region , the occurrence of seemingly contradictory extreme rainfall events is expected to increase.”
high exposure
Lane-Visser said about 24% of all roads in the city fall into high-exposure areas, meaning they are considered at risk of damage or destruction from severe weather.
“What is even more concerning is that more than half (52.6%) of the city's medium-sized taxi ranks are located in these high-risk zones. In addition, 13.6% of MyCiti stops and stations and 23% of GABS [Golden Arrow Bus Services] Bus stops are highly at risk, with a third of all train stations and 23% of tracks located in high-risk areas. ” In addition, 6% of national highways within the city limits pass through high-risk areas.
In addition to his analysis, Lane Visser also modeled three specific climate-related hazards separately (coastal flooding, low-lying inundation, and fire vulnerability) to determine the relative risk contributions of each and their impact. He said he emphasized geographical differences.
“Almost 27% of minibus taxi routes and 35% of daily stops are in high-risk areas. As such, bad weather could cause major disruption to almost a third of the city's taxi routes. The MyCiti network uses much of the coastline of the Atlantis Corridor, and approximately 15% of the network is at risk of coastal flooding. The biggest threats to GABS are those affecting the suburbs that buses pass through. .”
The researchers said their analysis can provide planners and decision makers with information on how to improve urban resilience and where to reduce the vulnerability of urban transport infrastructure.
Vanderschulen said calibrating and maintaining infrastructure, adding new infrastructure, and developing appropriate response strategies are all prudent governance tasks that can minimize the risks that severe weather events pose to transportation systems. Stated.
Investments in fire protection protocols and disaster response plans will benefit the city, while infrastructure elevation will “significantly reduce the threat that low-lying flooding poses to traffic mobility.”