IIT Delhi and IIT Gandhinagar launch District Flood Severity Index

• Researchers from IIT Delhi and IIT Gandhinagar have developed a District Flood Severity Index (DFSI), which takes into account the average duration (in days) of all flood events in a district, the percentage of historically flood-affected area, the total number of deaths, the number of injured, and the district’s population.
• This index directly assesses the severity of floods in an area using annual data collected by the India Meteorological Department (IMD) since 1967 and the district’s population.
• It is the first major effort in India to prepare a district-based, observation-based measure of flood vulnerability and damage.
• India is one of the most flood-prone countries, where between 1975 and 2015, around 1.13 lakh flood-related deaths occurred, averaging 2,765 annually

Top 5 flood-prone districts according to DFSI score:

1. Patna (Bihar) – DFSI: 19.37
2. Murshidabad (West Bengal) – DFSI: 19.01
3. Thane (Maharashtra) – DFSI: 18.88
4. North 24 Parganas (West Bengal) – DFSI: 18.86
5. Guntur (Andhra Pradesh) – DFSI: 18.84

• Thiruvananthapuram district has had more than 231 flood events, averaging more than four per year.
• Districts such as Lakhimpur, Dhemaji, and Kamrup in Assam, and Gorakhpur and Ballia in Uttar Pradesh, have also seen more than 200 flood events in the last five decades.
• Chamoli in Uttarakhand is among the top 30, highlighting the severe impact of rare but intense events like Glacial Lake Outburst Floods (GLOFs).
• DFSI also points to growing flood risks in urban centres such as Mumbai, Pune, and Nagpur.
• Additionally, coastal areas in states like Tamil Nadu, Gujarat, Andhra Pradesh, and West Bengal are becoming increasingly vulnerable to cyclones and heavy rainfall events.

DFSI Criteria:

• The DFSI uses six factors divided into two categories.
• Flood magnitude factors: Average duration (in days) of all floods in a district, percentage of historically flood-affected area, and the district’s population.
• Flood impact factors: Total number of deaths and injured. In its current form, the index does not account for the aerial extent of flood-affected agricultural areas.