A recent study by researchers at the Indian Institute of Technology (IIT) Kharagpur has revealed a disturbing trend of increasing ecological droughts in India. Ecological droughts are a severe form of moisture stress that can have long-term effects on the country’s ecosystems, forests, and croplands. The study, which analyzed remote sensing data and used machine learning techniques, found that these droughts are driven by a combination of changing monsoon patterns, global ocean warming, and human interventions.
The research showed that ecological droughts are increasing in ecologically sensitive areas, including the Himalayas, Northeast India, Central India, and the eastern Indo-Gangetic Plain. These regions are experiencing a decline in vegetation health, known as “browning,” which can have significant impacts on the health and functioning of terrestrial ecosystems. The study identified two primary drivers of this crisis: dryness caused by a deficit in rainfall (meteorological aridity) and ocean warming.
The researchers used a Random Forest machine learning model to quantify the contributions of these drivers, finding that meteorological aridity was the most significant contributor to vegetation stress, followed by sea surface temperature (a proxy for ocean warming). The study also found that large-scale climate oscillations, such as El Niño and the Indian Ocean Dipole, were strongly associated with years of negative vegetation health index anomaly and ecological droughts.
Human intervention was also found to play a significant role in the rising ecological droughts. The study found that forests with large human modifications and low forest integrity were more vulnerable to droughts. The increasing human population and associated activities, such as traditional agriculture and land-use changes, are leading to forest degradation and fragmentation, which can further perturb regional moisture recycling and make ecosystems more vulnerable to aridity and browning.
The study’s findings have significant implications for India’s environmental sustainability and food security. With millions of people dependent on agriculture and forest-based ecosystem goods and services, the rising ecological droughts pose a serious concern. The researchers emphasize the need to integrate the ecological repercussions of droughts into policy-making and to combat their threats. By understanding the complex links between the atmosphere, land, and ocean, India can better plan for mitigation and adaptation to the adverse impacts of droughts on its vital ecosystems. The study provides a crucial new perspective on ecological droughts and their drivers, and highlights the need for urgent action to address this growing crisis.