Context: A recent study published in the Nature journal titled Residual flood damage under intensive adaptation found that Indo-Gangetic Plain (excluding West Bengal and Assam) and Meghalaya are most susceptible to future floods in India and need to employ flood protection for the next 875-1,000 years.

Key findings

• The Indo-Gangetic Plain (including the Indus and Ganga basins) includes the states and Union territories of Jammu, Kashmir and Ladakh, Punjab, Uttar Pradesh and Bihar.
• The study calculated the extent of flood protection that countries would need to employ in terms of years.

The Indo-Gangetic Plain needs to employ flood protection for the next 875-1,000 years.

• They estimated the global cost of employing adaptive flood measures — depending on local economic scenarios and cost adaptation measures — by quantifying the cost of residual flood damage (RFD).
• RFD refers to unavoidable increases in flood damage even under an adaptation strategy based on feasible adaptation costs.
• Adaptation strategy implies infrastructural measures employed to mitigate the risks posed by floods.
• According to the study's estimate, RFD in South Asia is estimated to be around four million while adaptive costs around three million.
• But the benefits from the measures employed are over 50 million under the RCP8.5/SSP5 scenario.

Residual Flood Damage (RFD)

• RFD is part of the total expected annual damage (EAD) outlay.
• It is calculated by subtracting past EAD (1970 - 2000) and future EAD estimates (set to 1,000 years).
• RFD (as part of the gross domestic product) remains high in eastern China, the northern parts of India, and the central regions of Africa.

Key Facts

• According to data from Central Water Commission, the total flood-related losses in India were estimated to be over Rs 37 lakh crore from 1953 to 2017.

About Indo-Gangetic Plains

• Indo-Gangetic Plain or North Indian Plain is an extensive north-central section of the Indian subcontinent.
• They run parallel to the Himalayas, from Jammu and Kashmir in the west to Assam in the east, and drain most northern and eastern India.
• The 0.70-million km2 fertile plain encompasses most of northern and eastern India, the eastern parts of Pakistan, virtually all of Bangladesh, and Nepal's southern plains.
• The region is named after the Indus and Ganges rivers. Major rivers in this region are the Ganges, Indus, and Brahmaputra. Their main tributaries are Yamuna, Chambal, Gomti, Ghaghara, Kosi, Sutlej Ravi, Beas, Chenab, Teesta, and Meghna.
• Vindhyas, Satpura Range, and the Chhota Nagpur Plateau mark the southern edge of the plains.