New Delhi, Apr 3 (PTI) Greening of India's Thar Desert could be due to the combined effects of climate change and human activities, such as groundwater pumping, a study has found.
Also known as the 'Great Indian Desert', the Thar is a dry, arid region marked by rolling sand hills. Spanning over more than 2 lakh square kilometres in area, the desert lies in northwestern India and southeastern Pakistan.
Researchers, led by those from the Indian Institute of Technology Gandhinagar, said that while climate change threatens life in drylands around the world, including arid and semi-arid regions, the Thar Desert "defies expectations".
Analysing satellite images between 2001 and 2023, the researchers found "a striking rise in vegetation growth and urbanisation".
One of the world's most densely populated deserts, the Thar showed a 50-800 per cent rise in urban areas during 1985-2020 -- the highest among the 14 major deserts in the world, including the Arabian desert, according to the study.
"While many arid regions face worsening droughts, the Thar has become a hub of agricultural and urban growth over the past two decades," the authors wrote in the study published in the journal Cell Reports Sustainability.
Previous studies have highlighted greening trends in the Thar over recent decades. An August 2023 study, published in the journal Earth's Future, projected that the desert could turn green in the next century.
However, factors driving the Thar's greening remain unknown, the study's authors said.
Their analysis revealed that increased rainfall during monsoons is the main driver of greening, while groundwater pumping is the main factor contributing to greening during non-monsoon seasons.
"The (Thar) region experienced a significant increase (38 per cent) in mean annual greenness during 2001-2023, supported by precipitation increase (45 per cent contribution) and ground-water pumping (55 per cent contribution)," the authors wrote.
Further, challenges to sustain the growth in the future remain, the team said.
Overuse of groundwater and erratic rainfall could reverse gains, thereby risking food security and livelihoods, they said.
They added that rising temperatures and a dwindling water supply during dry seasons may endanger rapid urbanisation and intensive agriculture.
"Sustainable practices -- efficient water management, drought-resistant crops, adaptation to rising heat stress, and renewable energy -- must guide future development," the authors wrote.
The study's findings could inform policy decisions on advancing sustainable practices and fostering climate-resilient agriculture, they said.
For the analysis, rainfall data was taken from five datasets, including those from the US' NASA, the European climate agency, and the Indian Meteorological Department. Data from the Minor Irrigation Census, provided by the Ministry of Jal Shakti, Government of India, was also used.