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N Venkata Sathya Vivek

Nannaka Venkata Sathya Vivek supervised by Dr. Rehana Shaik received his Master of Science – Dual Degree  in Computer Science and Engineering (CSE). Here’s a summary of his research work on  Observational Analysis of Compound Warm, Dry, Wet and Cold Climate extremes in India:

The simultaneous occurrence of climate extremes poses significant threats to ecosystems, amplifying the vulnerability to various physical risks. A compound extreme event corresponds to a situation in which multiple extremes occur at the same time, leading to more severe impacts than individual extremes. Despite extensive research on individual hot extremes and droughts globally, and the development of numerous indicators to detect and study changes in extreme events across space and time, there remains a substantial gap in understanding the occurrence, magnitude, spatial extent, and associated risks of compound extremes. Most current climate extreme indicators do not provide information on compound or concurrent events. These compound extremes encompass scenarios such as warm/dry, cold/dry, warm/wet, and cold/wet conditions. Comprehensive research integrating multiple climate variables is crucial to address this gap, providing a holistic understanding of the risks and impacts associated with compound extremes. This study aims to fill this gap by investigating various compound extreme scenarios through the analysis of combinations of maximum temperature (Tx) and the Standardized Precipitation Evapotranspiration Index (SPEI). The analysis uses monthly data from 1951 to 2014, obtained from the India Meteorological Department (IMD) for the Indian landmass. The results of the study reveal several key trends and patterns in the spatial extent and frequency of compound extreme events. Notably, the spatial extent of warm/dry events has increased at a rate of 1.8% per decade, indicating a significant upward trend. Conversely, cold/wet events have shown a decrease of 1.1% per decade, highlighting a reduction in these events over the Indian region. Warm/wet events have also exhibited an increasing trend, albeit at a more modest rate of 0.3% per decade, while cold/dry events have shown a modest rise of 0.7% per decade. Furthermore, the study examines the frequency and return periods of these compound extreme events. It is observed that compound warm/dry and cold/wet extremes exhibit high frequency and shorter return periods, posing greater risks to the affected regions. On the other hand, compound cold/dry and warm/wet extremes occur less frequently, indicating longer return periods and consequently lower associated risks. The frequency analysis reveals that across much of the country, the occurrence of warm/dry, cold/dry, warm/wet, and cold/wet extremes ranges from 30-45 months, 15- 30 months, 20-30 months, and 25-45 months, respectively. A notable finding of the study is the increased frequency of warm/dry conditions in the recent period (1983-2015) compared to the base period (1951-1982). Specifically, the recent period experienced approximately 31 years of warm/dry conditions exceeding a spatial extent of 5%, whereas the base period had approximately 24 years. This trend underscores the growing prevalence of warm/dry extremes in recent decades. The findings of this study contribute to an enhanced understanding of the changes in compound climate extremes from a multivariate perspective. By examining the interplay between temperature and precipitation extremes, this research provides valuable insights into the evolving nature of climate extremes in India. The observed trends in the spatial extent and frequency of compound extremes have significant implications for climate risk assessment and adaptation strategies. The increasing trend of warm/dry events suggests a heightened risk of heatwaves and droughts, which can have severe impacts on agriculture, water resources, and human health. The study highlights the need for a comprehensive understanding of compound climate extremes to inform effective adaptation and mitigation strategies. Policymakers and stakeholders can leverage the findings of this research to develop targeted measures to enhance resilience against compound extremes. For instance, the increasing frequency of warm/dry conditions calls for improved water management practices, drought-resistant crop varieties, and heatwave preparedness plans. Moreover, the study emphasizes the importance of considering compound extremes in climate models and projections. Traditional approaches that focus on single variables may underestimate the risks associated with simultaneous extreme events. By incorporating compound extremes into climate models, researchers can better inform decision-making processes.

October 2024