  India is one of the worst affected countries in the world in terms of
fatalities and economic damage due to natural disasters, particularly floods.
For planning flood mitigating and relief measures, granular historical
information on a pan-India basis is required, which has been missing. Through
recent efforts, a few national scale datasets have been created, but they lack
the requisite information on fatalities and damages, which has limited the
ability to develop a flood severity index. This paper describes the development
of the India Flood Inventory with Impacts (IFI-Impacts) database, which
contains death and damage statistics, and combines population and historically
flooded area information sourced from a national hydrologic-hydrodynamic
modeling system. We also propose a novel District Flood Severity Index (DFSI),
which accounts for the historical severity of floods in India based on the
number of people they have affected and the spread and duration of such floods.
Districts being the administrative units of the government, this novel index
fulfills a major need and gap in currently available flood management tools.
The dataset as well as the index is expected to significantly advance disaster
preparedness towards floods in the country. DFSI can be improved further by
collecting and incorporating additional variables, e.g., economic losses and by
improving the reliability/robustness of the data of other variables. Based on
DFSI, actions need to be addressed to mitigate flood damages, beginning with
the districts with the high DFSI values.
