Application of Introducing Damaged Area Index for Cultivated Agricultural Lands Affected by Recurrent Tropical Cyclones Bulbul and Amphan Using Satellite Remote Sensing

South and Southeast Asian countries are prone to cyclones throughout the year due to climate changes. The damage is also severe due to tidal surges and intrusion of saline water in agricultural lands. Therefore, in this research, a damaged area index (DAI) of rice crop-based agricultural lands, affected by two consecutive tropical cyclones, was developed after assessing damaged type areas in the coastal region of Bangladesh. Repeatedly the cyclone Bulbul and Amphan struck India and Bangladesh’s coastline on November 10, 2019, and May 20, 2020, and both cyclones caused huge damage to rice crops and dominant agricultural lands. The study was conducted in 12 unions of Kalapara subdistrict under Patuakhali district, Bangladesh, to measure DAI for the crop calendar 2019–2020. It was found that cyclone Bulbul was more destructive than cyclone Amphan by using Landsat-8 OLI and TIRS datasets. A total of 10-DAI was calculated over the 30,907.59 hectares (ha) of agricultural lands. This study assessed two damaged areas-sets for the cyclone Bulbul and Amphan, respectively, those were defined as (1) not damaged (ND); (2) slightly damaged (SD); (3) moderately damaged (MD); (4) very damaged (VD); and (5) extremely damaged (ED) using damaged assessment area (DAA) method. The non-agricultural land use/land cover (LULC) areas were considered DAI-1 for the study. The DAI-6 to 9 areas for both cyclones were found at 6705.94 ha (21.70%); 8386.06 ha (27.13%); 7043.07 ha (22.79%); and 3994.51 ha (12.92%) respectively. A total of 420 ground reference points (GRPs) data were also investigated separately to validate the proposed DAI method of the research. A similar observation was found for the DAI-6 (ND to ED), 7 (SD to ED), 8 (MD to ED), and 9 (VD to ED) significantly from the GRPs validation consistently. Therefore, this study could help prepare a damage area index to support farmers with a new adaptive policy in recurrent cyclones for tropical cyclone-prone global south countries.