Assessment of impacts to the sequence of the tropical cyclone Nisarga and monsoon events in shoreline changes and vegetation damage in the coastal zone of Maharashtra, India

Manoranjan Mishra; Dipika Kar; Celso Augusto Guimarães Santos; Richarde Marques da Silva; Prabhu Prasad Das

doi:10.1016/j.marpolbul.2021.113262

Assessment of impacts to the sequence of the tropical cyclone Nisarga and monsoon events in shoreline changes and vegetation damage in the coastal zone of Maharashtra, India

Mar Pollut Bull. 2022 Jan:174:113262. doi: 10.1016/j.marpolbul.2021.113262. Epub 2021 Dec 27.

Authors

Manoranjan Mishra¹, Dipika Kar¹, Celso Augusto Guimarães Santos², Richarde Marques da Silva³, Prabhu Prasad Das⁴

Affiliations

¹ Department of Natural Resource Management & Geoinformatics, Berhampur University, India.
² Department of Civil and Environmental Engineering, Federal University of Paraíba, Brazil. Electronic address: celso@ct.ufpb.br.
³ Department of Geosciences, Federal University of Paraíba, Brazil.
⁴ ACOAST, Amity University Haryana Gurgaon, India.

PMID: 34968828
DOI: 10.1016/j.marpolbul.2021.113262

Abstract

The tropical cyclones impact both the eastern and western coasts of India, causing severe socio-environmental problems. This study analyzed shoreline changes and vegetation degradation caused by cyclone Nisarga and monsoon events in Maharashtra coastal zone and Mumbai region, India. In this study, the shoreline change was studied using the Net Shoreline Movement (NSM) statistical technique embedded in the digital shoreline analysis system (DSAS) tool. The effects of the cyclone on the vegetation were mapped using the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and the rainfall distribution from Global Precipitation Measurement (GPM) data. The correlation between rainfall data and vegetation loss was analyzed using geographically weighted regression. The results also show that 90% of the events were concentrated in the 80-300 mm classes, being classified as sudden increases. This cyclone caused erosion in 56.32% of the shoreline; the highest erosion level was observed along the coastal zone of Maharashtra (near Mumbai city). Cyclone Nisarga has also impacted the vegetation loss most prominently in the region, with mean EVI in pre-cyclone equal to 0.4 and post-cyclone equal to 0.2. These eco-physical studies using geospatial technology are needed to understand the behavior of changes in shoreline and vegetation and can also help coastal managers plan for resilient coastal systems after the passage of tropical cyclones.

Keywords: Accretion; Cyclone; Erosion; Natural hazards; Vegetation index; Western India.

MeSH terms

Cyclonic Storms*
India