Satellite study reveals 40 per cent of SGNP forests in poor health

A study based on highresolution satellite imagery to establish forest health at the Sanjay Gandhi National Park SGNP has found that lowhealth forests accounted for 3952 per cent healthy forests accounted for 3651 per cent and very healthy forests accounted for 336 per cent of the total area of the parkThe study mdash lsquoAssessing Forest Health of Sanjay Gandhi National Park Mumbai Maharashtra Indiarsquo mdash was conducted in January 2024 by Dr Ravindra Medhe with assistance from his student Chaitanya Kolekar using remote sensing data and GIS software for the analysis The report was published in IntechOpen on May 8 2025SGNP is located in a highly urbanised and ecologically sensitive region According to the researchers the integration of remote sensing and GIS techniques using Sentinel2A satellite data for analysing forest health through key vegetative indices is both timely and methodologically soundThe study excels in its multiindex approach by utilising Normalised Difference Vegetation Index NDVI to measures vegetation ldquogreennessrdquo and vigor Green Normalised Difference Vegetation Index GNDVI mdashsimilar to NDVI but more sensitive to chlorophyll content and photosynthetic activity mdash Modified Soil Adjusted Vegetation Index MSAVI technique mdash which reduces the influence of bare soil in vegetation analysis mdash and Moisture Stress Index MSI technique which indicates moisture stress in vegetationDr Medhe assistant professor of geoinformatics Department of Geography Savitribai Phule Pune University said ldquoParticularly commendable is the decision to include MSI to incorporate a hydrological perspective adding depth to the traditional greennessbased assessments The weighted overlay method while only applied to the vegetative indices provides a robust classification of forest health into three categories lowhealth healthy and very healthy forests This classification is clear intuitive and relevant for urban forestry managementrdquoThe authors of the study also effectively emphasise the impact of urbanisation and moisture stress on forest health which is a critical concern for conservation planning in metropolitan regionsThe study also shows comparisons to similar studies conducted in India and abroad Moreover the graphical outputs and indexspecific discussions enhance the readerrsquos understanding of spatial patterns and forest conditions within SGNPCommenting on the revelations of the study which indicated that only 336 per cent of the total area of SGNP is ldquovery healthyrdquo Dr Medhe said ldquoThis is not satisfactory as very healthy forest area is too little We must work to improve the quality and amount of SGNP forest land The forest health of SGNP is currently in a fragile state and not fully satisfactory Immediate and sustained conservation efforts are needed to restore lowhealth areas and protect the remaining healthy zonesrdquoQuestioned about the reason for the fragile state of SGNP Dr Medhe said ldquoAs a researcher I recognise the importance of supporting claims with rigorous multitemporal and interdisciplinary data While the study provides a valuable baseline assessment of forest health in SGNP it also highlights several areas where further investigation is essential to fully understand the drivers behind the observed forest degradation based on the existing literature spatial patterns and ecologicalcontext of SGNPrdquo33637Forest area classified as very healthyPossible reasons for degradationUrban pressure encroachmentThe parkrsquos location within one of the most densely populated metropolitan regions subjects it to continual landuse change illegal settlements and infrastructure developmentWater stress and climate variabilityEvidence from the Moisture Stress Index in this study combined with known regional climate variability suggests that periodic drought and declining groundwater availability could limit forest regeneration and productivityTourism human activitiesSGNP is a forest reserve tourist attraction and religious site which increases footfall and contributes to ecosystem disturbances like trail erosionLimited buffer zonemanagement challengesA relatively narrow buffer zone and a complex urbanecological interface present ongoing challenges to forest protection and longterm planningInvasive speciessoil issuesAnecdotal observations and prior studies from similar tropical dry deciduous forests suggest the presence of invasive plants and degraded topsoil especially in humandisturbed zonesatOptionskeyd0ddb8ef8f1a62a8cdd22fac27fc5ea7formatiframeheight90width728params