Assessing Agricultural Damage from Cyclones with the Disaster Vegetation Damage Index: A Study in Coastal Purba Medinipur, West Bengal

The North Indian Ocean (NIO) accounts for nearly 8 percent of all tropical cyclones that occur worldwide, and approximately 75 percent of the genesis of NIO tropical cyclones originates in the Bay of Bengal (BoB) basin. Cyclones form in the BoB during the pre-monsoon (April–May) and post-monsoon (October–November) seasons. Moreover, cyclone intensity is increasing during the pre-monsoon phase. This study focuses on Cyclones Fani, Amphan, and Yaas as the three most recent pre-monsoon cyclones, which recorded maximum sustained wind (MSW) speeds of 150, 145, and 65 knots, respectively. Cyclone Amphan resulted in widespread flooding in the coastal Blocks of Purba Medinipur, impacting 56 sq km of agricultural land in Khejuri-I, 42 sq km in Nandigram-II, and 42 sq km in Khejuri-II blocks collectively. However, the link between flooded land and crop loss does not yield a precise estimate of the potential impact, thus necessitating the use of Disaster Vegetation Damage Index (DVDI), which estimates the extent of crop and vegetation damage caused by disaster events such as cyclones and cyclone-induced floods. A DVDI score of below (-0.4) signifies very severe damage. Cyclone Fani inflicted substantial damage to 0.7% (10 sq. km), Cyclone Amphan inflicted damage to 40% (542 sq. km) of the total cropland area, and Cyclone Yaas affected 5.77% (78 sq. km) of the area severely. There is less chance of crop damage if farmers adjust their crop calendar by quickly harvesting, threshing, and drying the grains before the occurrence of a cyclone. Moreover, cultivating rice along with vegetables and using flood-resistant rice seed varieties such as Patni, Mali-4, and Jamin can enhance resilience against cyclone-induced flooding and minimize crop loss.