Utilizing Insights from 2018 Kerala Floods Damage Survey in Catastrophe Flood Modeling

In August 2018, the state of Kerala in India witnessed one of the worst floods in more than a century. The floods took 474 lives, affected 54 lakh people, and resulted in an estimated loss of over ₹ 15,800 crore.

To identify the extent of the flood damage, a team from AIR Worldwide (AIR), Hyderabad performed a comprehensive post disaster survey across the most affected sites of Kerala to gather information about damage extent, flood depths, and severity. The team travelled around 680 kms and visited more than 15 of the worst affected places across four districts. The information gathered from such events is a vital information to inform, evaluate, and validate catastrophic flood models. AIR develops such flood models across the globe to estimate flood risks to a variety of building structures and contents therein. With this experience and information, we can provide expert insights to clients on current and future flood events. The flood depths and extents measured during this survey were compared with AIR 100-year flood depths and were found to match reasonably well.

The lessons learned from this damage survey can be used to develop region specific damage functions (relation between flood depth and building damage) that would enable more accurate occupancy or construction specific flood losses. In this paper, we will show (i) extents of the damage from our survey, (ii) business interruption in the industrial sector, (iii) commercial and residential impacts, and (iv) how we can use this information to inform and validate our flood models.