By Our Reporter
SHILLONG, Jan 8: Shillong, once known for its cool and temperate climate, is experiencing a steady rise in land surface temperature (LST), a phenomenon closely linked to urbanisation and changes in land use and land cover (LULC). A study has highlighted how growing urbanisation over the last 30 years has led to a rise in temperatures, creating what scientists call the Urban Heat Island (UHI) effect—a phenomenon where cities become significantly hotter than their rural surroundings.
The study, conducted using advanced modeling techniques like CA-Markov and Google Earth Engine, analysed Shillong’s LULC and surface temperatures from 1993 to 2023. It reveals that settlement areas have expanded by 10.96% over the past 30 years, primarily at the expense of agricultural land, vegetation, and water bodies. As built-up areas increased, so did the land surface temperature, with settlement areas registering an average temperature rise of 4.3°C during the period.
The study has been published in Remote Sensing, an international, peer-reviewed, open-access journal focused on the science and application of remote sensing technology.
Using satellite technology, the researchers examined how Shillong’s land has been used and how it has changed over the years. The study reveals that settlement areas—spaces with houses, roads, and buildings—have expanded by nearly 11% since 1993. This expansion has come at the cost of greenery, farmland, and water bodies, which used to keep the city naturally cool.
Over three decades, the average temperature in densely populated areas has gone up by 4.3°C. In 1993, the temperature in such areas was around 17.45°C; by 2023, it had risen to 21.75°C. Even vegetated zones—areas with trees and plants—have not been spared, with temperatures there increasing by 4°C.
In 1993, nearly 28% of Shillong was pleasantly cool, with temperatures below 12°C. Fast forward to 2023, and that number has dropped to almost zero. Instead, most of the city now has temperatures between 17°C and 23°C, making Shillong warmer than it used to be.
The study blames urban growth. As more people moved into the city, houses and roads replaced fields, forests, and water bodies. For example, barren land (open spaces without greenery) has reduced drastically—from 40% of Shillong’s area in 1993 to just 7% today. Meanwhile, settlements now cover nearly 17% of the city and are projected to occupy 28% by 2050.
While Shillong’s tribal rules protect forested areas from indiscriminate tree-cutting, other types of green spaces are shrinking. This reduction in greenery affects the city’s natural cooling process, as trees and water bodies help absorb heat and keep temperatures low.
The rising temperatures are more than just numbers. They mean, hotter days for residents, making life uncomfortable, increased strain on Shillong’s limited resources, like water and electricity and negative effects on the city’s delicate environment.
Additionally, the replacement of natural land with concrete and asphalt leads to less rainwater being absorbed into the ground. This results in falling groundwater levels and increased surface runoff during heavy rains, causing more flooding in urban areas.
Similar studies, such as one in Bangladesh, show that hotter cities also put their people at risk of heatwaves. Experts stress the importance of considering how urban growth affects not just the environment but also the health and well-being of residents.
The study emphasizes the urgent need for sustainable urban planning, like preserving green spaces, Creating parks, plant trees, and protect water bodies, Raising awareness about the benefits of protecting Shillong’s natural environment, Ensuring future development is balanced and prioritizes the environment and advanced tools can help plan the city better, predicting which areas are most at risk from rising temperatures.
While Shillong’s skyline continues to change, the challenge lies in ensuring that its climate and character remain intact for future generations.