With extreme weather conditions posing an increasing threat to lives and assets, South Africa’s disaster management capacity needs to include better early warning systems for key risks such as flooding, consultancy SRK Consulting says.
SRK Consulting senior civil engineer Natasha Ramdass says early warning systems can significantly reduce the impact of flooding on lives.
“The importance of early warning has been well demonstrated in terms of saving lives in the face of flood disasters. Although the economic losses caused by flooding events have increased by 50 times over the past 50 years, the loss of life has reduced by a factor of ten,” she notes.
Underpinning this trend has been the paradigm shift away from post-disaster response, and toward a more proactive risk reduction approach. This has required meteorological, hydrological and climate services to support science-based risk management decisions – alongside more investment in early warning systems.
“Early warning systems for weather-related disasters such as flooding have been developed and tailored over the past decades across the world. First world countries have invested time and resources on tailoring their early warning systems for their respective application, climatic conditions and data availability,” Ramdass notes.
The need for these systems is no less urgent in South Africa, where the National Climate Change Adaptation Strategy has been developed in anticipation of both positive and negative rainfall trends, SRK says.
In Durban, for instance, the city’s rainfall is expected to increase by 500 mm by 2100, it states.
“In addition to that, average temperatures will rise by between 1.5 °C and 2.5 °C by 2065, along with heat waves and higher intensity rainfall events,” Ramdass notes.
She highlights that government has raised national priorities for human settlements disaster risk reduction and management provisions, as well as calling for early warning networks for disaster management to be expanded.
“SRK has been engaging with disaster management issues for many years, applying our multidisciplinary expertise in hydrology, hydraulics, geosciences, water-quality management infrastructure development and other fields to help clients mitigate and adapt to the related risks,” she points out.
Lightning is a related hazard that is attracting more attention in terms of disaster management and early warning systems, says SRK hydrologist Byron Gray.
It causes significant injury, death and damage to infrastructure yearly – and South Africa has one of the highest incidences of lightning-related injuries and deaths, he states.
“There has been considerable progress in developing facilities for early warning, with South Africa now equipped with a ground-based lightning detection network – one of only three in the southern hemisphere.
“This is significant, as lightning is predicted to increase with climate change, raising the vulnerability of especially rural communities,” Gray says.
Meanwhile, Ramdass says the foundation of early warning systems for flooding comprises the specialised understanding of water engineering and meteorology data management, paired with the knowledge of specific operations technology – to achieve acceptable confidence levels.
It is also vital to deliver quality data to systems, requiring careful monitoring and checking procedures, she notes.
This will underpin the four key functions in an effective early warning system: risk analysis, to understand what and who is going to be affected, and when; monitoring and warning, to understand what kind of warning is related to that risk; dissemination and communication, to warn the relevant people timeously; and the response capability, to ensure that action is planned and appropriate.