Impact assessment of Cyclone Yaas on the mangrove forest area in the Bhitarkanika National Park (India)

Abstract

Tropical Cyclone Yaas inflicted substanntial damage on Bhitarkanika National Park (BNP), an eminent wildlife sanctuary housing a vast diversity of flora and fauna, during its occurrence in 2021. The park has experienced a heightened frequency of cyclonic activity in recent years. This study undertakes a comprehensive analysis of the impacts of Tropical Cyclone Yaas on the mangrove forest within BNP, utilizing a broad array of physical, biological, and ecological indices. The assessment method employed in the study encompasses various indicators, such as ecological (Normalized Difference Vegetation Index – NDVI, Enhanced Vegetation Index – EVI, Leaf Area Index – LAI, Normalized Difference Water Index – NDWI, and Normalized Difference Salinity Index – NDSI), biological (Chlorophyll content and Gross Primary Productivity – GPP), and physical (flood monitoring and precipitation) measures. Our findings elucidate the destructive consequences of Cyclone Yaas on the mangrove forest, inflicting significant ecosystem loss attributable to the extreme precipitation and high wind speeds. The biophysical, ecological, and biological indicators reveal profound effects on the local ecosystem, manifested through a decline in vegetation vigor and alterations in soil conditions, notably marked by an increase in salinity.