A global multi-hazard risk analysis of road and railway infrastructure assets published in Nature Communications has attempted to measure the cost of natural disasters to the world’s roads and railways, suggesting around 73 per cent of this damage would be due to surface water caused by extreme rainfall and river flooding.
Global Expected Annual Damages (EAD) due to direct damage to road and railway assets range from 3.1 to 22 billion US dollars, of which about 73% is caused by surface and river flooding.
Global EAD are small relative to global GDP (approximately 0.02%).
However, in some countries EAD reach 0.5 to 1% of GDP annually, which is the same order of magnitude as national transport infrastructure budgets.
A cost-benefit analysis suggests that increasing flood protection would have positive returns on approximately 60% of roads exposed to a once-in-a-century flood.
This supports ALGA’s call for the Commonwealth to provide greater funding for mitigation measures.