Assessing Cyclone YAAS’s Induced Impact on Vegetation Using Multiple Indices: A Case Study on Assasuni Upazila of Bangladesh

¹ Institute of Disaster Management, Khulna University of Engineering & Technology
² Department of Urban and Regional Planning, Khulna University of Engineering & Technology

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Tropical cyclones are the most destructive natural disaster, resulting in massive damage to vegetation, infrastructure, and livelihoods. Due to unique geographical location, Bangladesh’s coastal area often experiences the devastating effects of the natural disaster. This study assesses the impact of cyclone YAAS on vegetation in May 2021. Three indices (DVDI, DNDVI, and DEVI) were used to evaluate the vegetation damage in Assasuni Upazila (Bangladesh). Sentinel-2A satellite imagery was processed via the Google Earth Engine (GEE) platform. The study found that DNDVI, with an AUC of 0.833, is the most accurate index for detecting vegetation damage after a cyclone, surpassing DEVI and DVDI. DVDI shows the highest severe damage (31.92%) compared to other indices. The study also examined how six topographic factors relate to the most effective damage index using both linear and nonlinear methods. Elevation showed a moderate correlation (R² = 0.3993), indicating that areas at higher elevations tend to experience less damage, likely due to reduced exposure to storm surges. Storm surge height showed the strongest polynomial relationship (R² = 0.5708). The study’s findings can enhance coastal resilience against future cyclones by implementing land use planning and restoring natural barriers, thereby enhancing global disaster preparedness and climate adaptation efforts.