Srinagar, Oct 5: Srinagar’s land surface temperature increased by up to 4°C between 2001 and 2021, alongside declining vegetation cover and rising PM2.5 concentrations due to city’s rapid urban expansion, a new study published in GeoJournal has found.
The study, titled “Quantifying the environmental impacts of urban expansion in Srinagar City, Jammu & Kashmir, India through remote sensing and geostatistical analysis,” examined changes in the city over two decades using satellite observations and geostatistical techniques.
Researchers Amjed Ali, Kheraj and Arshad Ahmed from the Department of Geography, Central University Haryana, found that PM2.5 (complex, toxic mixture of microscopic solids and liquid droplets including elements like organic chemicals, heavy metals, dust, soot, and smoke) concentrations increased by as much as 3.9 micrograms per cubic metre, with the most pronounced changes recorded in central and south-western parts of Srinagar.
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The study found a significant association between vegetation loss, air pollution and surface warming. Its regression analysis indicated that declining vegetation and PM2.5 levels contributed significantly to variations in land surface temperature, with the model recording an R² value of 0.46.
The researchers, however, cautioned that PM2.5 variability could not be explained entirely by surface temperature and vegetation cover, suggesting that other factors also influence Srinagar’s air quality.
The findings were based on satellite-derived land surface temperature, vegetation measurements obtained through the Normalised Difference Vegetation Index (NDVI) and PM2.5 estimates from AOD-GEOS-Chem datasets. The researchers combined the indicators using a grid-based analytical framework and applied Mann-Kendall trend analysis and multiple linear regression.
The study also found that more than half of Srinagar fell within moderate-to-poor environmental quality categories under the Environmental Quality Index developed by the researchers.
According to the study, the expansion of built-up areas and replacement of natural surfaces with impervious urban materials have altered the city’s surface energy processes and contributed to urban heating.
“Such changes alter surface energy processes and can intensify urban heating, while the loss of vegetation reduces the natural cooling and pollution-filtering functions of green spaces,” the study said.
The researchers noted that vegetation has a dual role in urban environments, helping regulate temperatures through evapotranspiration while also filtering pollutants from the air.
“Vegetation plays a key role in regulating urban temperatures through evapotranspiration and can also help improve air quality by filtering pollutants,” the study noted.
The spatial analysis showed that central and south-western areas of Srinagar experienced particularly significant changes, with rising surface temperatures and PM2.5 concentrations occurring alongside declining vegetation cover.
The researchers said the findings underline the need to address Srinagar’s urban growth and environmental management as interconnected issues rather than treating temperature, vegetation and air pollution separately.
They called for integrated urban planning, stronger green infrastructure and improved pollution-control measures, arguing that the city’s environmental management needs to keep pace with its expansion.
The study places Srinagar’s experience within a wider challenge faced by rapidly urbanising cities, where development can outpace the capacity of infrastructure and environmental management systems.
“Managing the city’s future growth will require greater attention to environmental sustainability, including the protection and development of green infrastructure and measures to address pollution,” the study stated, linking the recommendations to the broader objectives of Sustainable Development Goal 11 on sustainable cities and communities.
