I am tasked with determining general depth-damage functions for road assets including tunnels, culverts, roads and bridges for the primary road network of a country in the Balkans.

I will be receiving flood hazard maps containing flood depth at various return intervals. I also have the locations of the aforementioned assets including the entire road network. Finally it would not be difficult to obtain a DEM of the area. From these materials (especially the flood hazard map) I would have to determine percent damage for each road asset. This could be a percentage of replacement cost or an index for actual structural damage.

I spent a lot of time looking for ready-made damage depth functions and looked through the HAZUS docs, HEC-FIA user manual, Riskscape docs and global databases such as the one by Huizinga "Global flood depth damage functions database". I also sought to find the 2007 "Flood damage functions for EU member states" but this appears to be a confidential report.

In all the available literature I could find, the damage-depth function concept appears limited to computing damage for buildings and businesses. There is little on bridges and even less on culverts and roads.

For our project the buildings are of no consequence. How can I come up with thought out damage depth functions to apply for transportation network assets in this project?

Thanks