Q. "Discuss the relationship between Indian summer monsoon variability and marine productivity in the Bay of Bengal. How can disruptions in monsoon patterns affect food security in the region?"
Introduction:
A recent study published in Nature Geoscience highlights the strong correlation between Indian summer monsoon variability and marine productivity in the Bay of Bengal (BoB). By analyzing sediment cores spanning 22,000 years, researchers found that extreme monsoon conditions—both strong and weak—disrupt ocean mixing, reducing plankton growth, a key component of the marine food web.
Monsoon Variability & Marine Productivity:
- Nutrient Upwelling & Plankton Growth:
- The Bay of Bengal, though covering <1% of global ocean area, contributes ~8% of global fishery production due to nutrient-rich coastal waters.
- During normal monsoons, wind-driven upwelling brings deep nutrients to the surface, boosting phytoplankton growth.
- However, excessively strong monsoons cause excessive freshwater influx, creating a stratified ocean layer that prevents nutrient mixing.
- Weak monsoons reduce wind-induced upwelling, leading to nutrient scarcity.
- Historical Evidence:
- The study reveals that past extreme monsoons led to a 50% decline in marine food availability, disrupting the entire aquatic food chain.
Impact on Food Security:
- Fisheries & Livelihoods: Over 200 million people depend on BoB fisheries for protein and income. Reduced plankton growth diminishes fish stocks, threatening coastal economies.
- Climate Change Link: Global warming is expected to intensify monsoon variability, worsening disruptions in ocean productivity.
- Socio-Economic Consequences: Decline in fish catch could increase malnutrition and poverty in littoral states like India, Bangladesh, and Myanmar.
Way Forward:
- Climate-Resilient Fisheries: Promote sustainable fishing practices and aquaculture to buffer against productivity shocks.
- Enhanced Monitoring: Strengthen oceanographic research to predict monsoon-induced productivity changes.
- International Cooperation: Collaborative management of BoB resources among neighboring countries is crucial.
Conclusion:
The study underscores the delicate balance between monsoon dynamics and marine ecosystems. With climate change exacerbating monsoon variability, proactive measures are needed to safeguard marine productivity and food security in the Bay of Bengal region.
Link to UPSC Syllabus:
- GS Paper I (Geography): Salient features of world’s physical geography; changes in critical geographical features (including water bodies and ice-caps).
- GS Paper III (Environment & Ecology): Conservation, environmental pollution and degradation; Environmental impact assessment.
- GS Paper III (Disaster Management): Effects of climate change on marine ecosystems and food security.
Link to Previous Year Questions:
- 2022: “Discuss the impact of climate change on the Indian monsoon system and its implications for agriculture.” (GS I)
- 2021: “Examine the role of oceanic productivity in sustaining marine biodiversity and coastal livelihoods.” (GS III)
- 2019: “How does the Indian monsoon affect the ecological balance of the Bay of Bengal?” (GS I)
Q. Discuss the implications of the IMD’s prediction of an 'above normal' monsoon for 2025 on India’s agriculture and disaster preparedness. How can India balance the twin challenges of maximizing agricultural productivity and minimizing monsoon-induced disasters?
Introduction
The Indian Meteorological Department (IMD) has predicted an ‘above normal’ monsoon for June–September 2025, following a similar trend in 2024. Such forecasts bring optimism for kharif crop production, particularly pulses and cereals, and support food security and export potential. However, history shows that excessive monsoon rains can also cause severe flooding and landslides, emphasizing the dual-edged nature of monsoon dependence in India.
Body
Implications of ‘Above Normal’ Monsoon
- Positive Agricultural Outcomes:
- Improved Kharif Sowing: Adequate rainfall enhances sowing of crops like rice, pulses, and oilseeds.
- Food Stock and Export Boost: Surplus production strengthens buffer stocks and supports exports.
- Reduced Import Bill: Government procurement of pulses at MSP can reduce dependence on imports, aided by better yields due to good rainfall.
- Meteorological Factors Supporting the Forecast:
- Absence of El Niño: El Niño usually weakens monsoons; its absence improves rain prospects.
- Below-Normal Eurasian Snow Cover: IMD notes an inverse relationship — less snow implies more rain in India.
- Oceanic Neutrality: With oceanic parameters being neutral, sub-continental dynamics like cyclonic activity will influence rainfall distribution more heavily.
- Challenges and Risks:
- Disasters from Excess Rainfall: Floods, landslides, and waterlogging, such as the 2024 Wayanad tragedy, remain persistent risks.
- Urban Infrastructure Stress: Cities lack drainage resilience; heavy rains lead to paralysis and property loss.
- Climate Change Amplification: Global warming exacerbates monsoon variability, intensifying both droughts and floods.
Way Forward
- Strengthen Early Warning Systems: Improve short-term rainfall and flood forecasting using AI and satellite data.
- Disaster-Resilient Infrastructure: Build embankments, landslide barriers, and climate-resilient housing in vulnerable zones.
- Agro-Advisories and Insurance: Disseminate IMD updates to farmers and promote crop insurance under PMFBY to hedge risks.
- Integrated Watershed Management: Focus on rainwater harvesting, recharge wells, and better irrigation practices to utilize excess rainfall.
- Urban Drainage Planning: Upgrade stormwater systems and regulate construction in ecologically fragile zones.
Conclusion
India’s monsoon remains a critical determinant of agricultural productivity and economic stability. While an ‘above normal’ monsoon offers significant opportunities, it also demands calibrated preparedness against climate-induced disasters. A balanced strategy combining scientific forecasting, resilient infrastructure, and climate-smart agriculture is key to harnessing monsoons sustainably.
Linkage to Previous Years’ Questions:
- UPSC 2022 GS Paper 3: “Discuss the role of the Indian monsoon in India’s agriculture. How is it influenced by global climatic phenomena like El Niño?”
- UPSC 2019 GS Paper 3: “Disaster preparedness is the first step in any disaster management process. Explain how hazard zonation mapping will help disaster mitigation in the case of landslides.”
- UPSC 2017 GS Paper 3: “Examine the impact of climate change on the Indian monsoon and suggest appropriate mitigation strategies.”
Q. Recent studies using high-resolution satellite data have shown changing spatial patterns and timing of monsoonal rainfall over India. Examine the causes and implications of these spatial and temporal shifts in monsoonal rainfall patterns in the last two decades.
Introduction:
Recent findings based on the GSMaP-ISRO precipitation data (2000 onwards) indicate notable spatial and temporal changes in India’s monsoonal rainfall during the decade 2011–2020 as compared to 2001–2010. The spatial distribution and timing of peak rainfall have undergone regional shifts, reflecting deeper climatic and environmental dynamics.
Body:
- Spatial Trends in Rainfall:
- West-central India witnessed an increase of ~2 mm/day in rainfall during 2011–2020.
- Indo-Gangetic Plain and southernmost regions showed slight increases.
- In contrast, eastern and northeastern India, which had higher rainfall in 2001–2010, experienced a decline of ~1 mm/day in the recent decade.
- Causes of Spatial Changes:
- Vegetation Growth: Rise in NDVI (0.2 → 0.4) in west-central India suggests enhanced vegetation cover, promoting evapotranspiration, cloud formation, and rainfall.
- Soil Moisture: A positive feedback loop with vegetation and rainfall was observed in west-central India.
- Temporal Shifts in Rainfall Peaks:
- Indo-Gangetic Plain: Peak rainfall advanced by 2–4 hours.
- West-central India: Delayed by 1–2 hours.
- Influenced by aerosol loading: Higher aerosols over Indo-Gangetic Plain lead to early peaking; lower aerosols in west-central India delay rainfall.
- Implications:
- Agricultural Planning: Timing of peak rainfall affects sowing and irrigation schedules.
- Water Resource Management: Shifting patterns challenge reservoir operations and urban drainage.
- Disaster Preparedness: Regional floods and droughts may not align with past trends, requiring updated models.
Conclusion:
The findings underscore the interplay between land-use changes, aerosols, and rainfall dynamics, demanding region-specific adaptive strategies in agriculture, climate resilience, and disaster risk reduction.
Linkages to Previous Year UPSC Mains Questions:
- GS1 2022 Q12: Why is the Indian monsoon unique in nature? Discuss the recent trends and anomalies in its behaviour and the impact on agriculture.
- GS3 2020 Q6: How and to what extent would micro-irrigation help in solving India’s water crisis? (Indirectly linked to water use efficiency amid rainfall shifts.)
- GS1 2015 Q1: The recent cyclone on the east coast of India was called “Phailin”. How are tropical cyclones named? Describe the impact of cyclones on the eastern coast of India. (Relevant to regional precipitation extremes.)
- GS3 2014 Q13: Environmental Impact Assessment studies are increasingly being used to understand the impact of development on climate. Discuss with reference to changing rainfall patterns.