Dr Jonathan Clarke on Libya Flooding and Storm Daniel
“The tragic events following the collapse of a dam near Derna in the wake of Storm Daniel, are a reminder of how climate change is driving ever more extreme weather. Where once we would talk about extreme weather within the context of previous or anticipated events, recent years have seen storms, floods and heat waves of a magnitude that would have been unimaginable, just a few years ago. If we are to live with these growing risks, we must increase the resilience of our cities and settlements, improve and reinforce our critical infrastructure, and build community preparedness and capacity to cope.
I have worked on a project in the past (DESURBS), which looked at similar disasters to understand the causes. It sounds like there are parallels to the failure of the levees around New Orleans, following Hurricane Katrina.
We are seeing weather events that are not simply at the 'extreme' end of recorded weather, but absolutely off the scale from what we had previously considered normal.
The extremes issue is relevant to what we know about the dam. Inevitably it will have been designed for a particular set of risks/circumstances, so it is quite possible that it hasn't been designed to deal with the levels of water that it was inundated with. Maintenance and monitoring are also important and potentially could have led to the collapse.
If we compare it to New Orleans, one of the key issues is that there was no warning and that people didn't know what to do in the event of a dam collapse.”