Analysis of Mangrove
vegetation health index by implementing NDVI classification method based on Landsat
image data: Case study from Zuari Estuary Goa, India
Sawaikar Ranjita, Tari Shreeveni, Deshpande Tanvi and Prabhugaonkar Venkatesh
Res. J. Chem. Environ.; Vol. 29(1); 26-30;
doi: https://doi.org/10.25303/291rjce026030; (2025)
Abstract
Mangrove ecosystems are among the most productive and biologically complex ecosystems
in the world providing many ecosystem services for human wellbeing, hence they have
an outstanding relevance ecologically and economically. Mangrove habitats are temporarily
inundated and often located in inaccessible regions. In Goa, fringing mangroves
are distributed in Zuari and Mandovi estuaries based on topography and environmental
conditions. These estuarine regions are used as inland waterways for transportation
of iron ore, tourism, infrastructure development like bridges, jetties, highways,
resorts and hotels, residential apartments, restaurants, small roads etc. Zuari
estuary is located at lat. 15°25'N and long. 73°59'E on the central west coast of
India. The images were downloaded from United States Geological Survey website (USGS).
The radiometric and geometric corrections were made to reduce the undesirable noise
component and changes in the amount of incoming radiance from sensors.
Anderson level 1 classification was used for the classification purpose. The mangroves
were digitized using hybrid classification method. For mangrove demarcation Google
Earth Pro and visual interpretation techniques were used. Normalised Difference
Vegetation Index (NDVI) analysis was adapted to perceive the health status of mangroves
covers in the study area. The NDVI results were divided into three categories: (0.00-0.15
Stressed), (0.15-0.30 Moderately healthy), (0.30-0.47 Very healthy). Rhizophora
and 01sp. each of Aegiceras, Bruguiera, Kandelia, Acanthus and Excoecaria along
with mangrove associates like Acrosticum, Clerodendron, Salvadora, Ipomoea and Derris.
Sonneretia alba and Avicennia marina were found to be dominating followed by Rhizophora
mucronata. Stressed patches of mangroves can be attributed to the human interference
from the surrounding regions, changes in water salinity, increase in pollution levels
due to mining activities (transportation of iron ore from barges), infrastructure
development etc. Moderately healthy and very healthy patches of mangroves may be
associated with suitable ecological and natural conditions favouring healthy growth
and also lack of anthropogenic interference and awareness about the importance of
mangroves.
