In a recent study published in the Indian Journal of Science and Technology, researchers have uncovered alarming trends regarding the loss of tree cover and its impact on rising temperatures in the Chennai Metropolitan Area (CMA).
According to the study titled ‘Impact of Urban Vegetation Loss on Urban Heat Islands: A Case Study of Chennai Metropolitan Area’, conducted by the School of Planning and Architecture, Vijayawada, the CMA has witnessed a significant loss of vegetation, amounting to 13.33% between 2013 and 2022. This decline translates to a loss of 158.54 square kilometres out of the total 1,189 square kilometres of the CMA.
The study highlights that regions in the northern, central, and southern parts of the CMA have experienced the least vegetation compared to their western counterparts, primarily due to rapid urbanisation. As a consequence of this diminishing green cover, the land surface temperature (LST) in the area has witnessed a notable increase. In 2013, the maximum LST recorded was 37°C, with a minimum of 23.63°C. By 2022, these figures escalated to a maximum of 43.53°C and a minimum of 31.66°C, indicating a significant rise in temperature attributed to the loss of vegetation. Despite the overall decline in green cover, certain cool pockets such as rivers, lakes, forests, and marshes have persisted in the CMA. However, even these areas have witnessed a decline in coolness, with temperatures increasing from 23.63°C to 26°C in 2013 to 31.66°C to 33°C in 2022, owing to the diminishing cool pockets.
The study utilised the Normalised Difference Vegetation Index (NDVI), a remote sensing method, to assess vegetation density and distribution across the Chennai Metropolitan Area. This methodological approach provided valuable insights into the evolving landscape dynamics and underscored the urgent need for conservation efforts to preserve and enhance green spaces in urban environments. As cities continue to grapple with the impacts of urbanisation and climate change, addressing the loss of tree cover and its implications for rising temperatures is paramount. Implementing sustainable urban development practices and investing in green infrastructure are essential steps towards mitigating the adverse effects of temperature rise and fostering resilient communities for the future.
