Knysna fires were probably caused by lightning strike: CSIR

The fires that ravaged Knysna and surrounding areas in the Western Cape last year were probably caused by the spread of a smouldering fire after a lightning strike on March 22.

This is according to a report released by the Council for Scientific and Industrial Research (CSIR) on Thursday on what it called “one of the worst fire disasters” in South Africa’s history.

The report assessed the most likely sequence of events that led to the fire by using satellite images‚ drone video footage‚ lightning and weather data to investigate the spread of the fire in the first 45 minutes.

Two fires started on June 7 2017‚ one in Elandskraal and one in Kruisfontein. The CSIR report only focuses on the Elandskraal fire. A satellite first detected a patch of brown‚ dying vegetation on March 29.

“Satellite imagery indicates that the area of smouldering vegetation had grown to 3‚033 square metres by May 18 2017‚ prior to the Elandskraal fire.”

Information from the South African Weather Service suggests that a lightning struck on March 22 was the “most likely cause of the smouldering patch of vegetation‚ but this cannot be established for certain”.

On June 7‚ north-westerly berg winds blew up to 50 km/h by 3.30am and 55 km/h at 5.23am.

“This could have provided sufficient oxygen for a smouldering‚ underground fire to flare up.”

These findings somewhat echo the views of forensic investigator David Klatzow‚ who said in August last year the fire was probably started by a lightning strike on April 12.

Klatzow said at the time: “It is likely that [a lightning bolt] ignited something which was oxygen-limiting. [The fire] smouldered away until it got oxygen and the wind suddenly crept up on the morning of June 7.”

He added: “In the same way that if you would want to resurrect a fire that you started the night before‚ you would blow on it‚ is the same way it happened here.”

The CSIR used commercial satellite images as well as data from the International Charter on Space and Major Disasters‚ the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA).

They said this had presented them with a “gold mine” of data.

“Following reviews by local and international experts‚ the scientific report was submitted to fire managers‚ relevant stakeholders‚ such as the Southern Cape Fire Protection Association‚ the Western Cape’s Provincial Disaster Management Centre‚ Knysna municipality‚ International Charter on Space and Major Disasters and is now available to the general public.”