Analysis of Rainfall Trends and Variability in Eastern Himalaya: Evidence from Sikkim
DOI:
https://doi.org/10.70917/jcc-2025-031Keywords:
Sikkim Himalaya , Rainfall Variability, Rainfall Trend, SPI, PCI, ANOVA, Agricultural VulnerabilityAbstract
Since last century, Sikkim has witnessed substantial climatic fluctuations that can affect the local water availability, agricultural productivity, and livelihood security. Despite this growing concern, a limited study incorporated century-long datasets to explore the underlying climatic pattern of the state and often focuses only on trend analysis without applying a diverse set of statistical and spatial techniques. Hence, a comprehensive analysis has been employed to explore the long-term trend and variability of Sikkim’s yearly and seasonal precipitation patterns from 1923 to 2023.Several statistical matrices have been applied viz. Coefficient of Variation (CV), Analysis of Variance (ANOVA) and Tukey’s Honest Significant Difference (HSD) Test to analyze the intra-seasonal and inter-seasonal rainfall variability, Standardized Precipitation Index (SPI) has been used to find out wet and dry years, Precipitation Concentration Index (PCI) shows annual and seasonal rainfall distribution, Simple Moving Average method has been applied to detect long-term trend, Inverse Distance Weighted interpolation technique visualizes the spatial rainfall variation in the state. This research offers new insights into the precipitation behavior and shifting rainfall dynamics such as summer rainfall demonstrates the most significant inter-cluster difference, wet and dry events are significantly increasing in summer season, the highest variability in precipitation distribution can be observed in monsoon rain, the summer and winter rainfall is increasing, where monsoon rainfall is decreasing significantly over the region, monsoon rainfall shows significant increasing trend in Gyalshing and Mangan, where summer and winter rain is increasing at Gyalshing and Mangan. These findings can help in regional adaptation strategies, water resource management, agricultural planning, and minimize climate-related livelihood vulnerabilities, as most of the farmers of this state rely on rainfall for their irrigation purposes.
References
Abdi, H. & Williams, L. J. (2010). Tukeys Honestly Signi cant Di erence (HSD) Test. Encyclopedia of Research Design.
Abdi, H. (2010). Coe cient of Variation. Encyclopedia of Research Design.
Agada, I. O., Oguche, C. A., & Agada, P. O. (2018). Analysis of the variability in some climatic parameters in Oyo, Nigeria. Trends in Science & Technology Journal, 3(2), 401–406.
Arnell, N. W., Lowe, J. A., Bernie, D., Nicholls, R. J., Brown, S., Challinor, A. J., & Osborn, T. J. (2019). The global and regional impacts of climate change under representative concentration pathway forcings and shared socioeconomic pathway socioeconomic scenarios. Environmental Research Letters, 14(8). https://doi.org/10.1088/1748-9326/ab35a6
Azhoni, A. & Goyal, M. K. (2018). Diagnosing climate change impacts and identifying adaptation strategies by involving key stakeholder organisations and farmers in Sikkim, India: Challenges and opportunities. Science of the Total Environment, 626, 488–477. https://doi.org/https://doi.org/10.1016/j.scitotenv.2018.01.112
Azzarri, C., & Signorelli, S. (2020). Climate and poverty in Africa South of the Sahara. World Development, 125, 104691. https://doi.org/10.1016/j.worlddev.2019.104691
Basu, R., Misra, G., & Sarkar, D. (2021). A remote sensing based analysis of climate change in Sikkim supported by evidence from the field. Journal of Mountain Science, 18(5), 1256–1267. https://doi.org/10.1007/s11629-020-6534-0
Belay, A., Demissie, T., Recha, J. W., Oludhe, C., Osano, P. M., Olaka, L. A., Solomon, D., & Berhane, Z. (2021). Analysis of climate variability and trends in Southern Ethiopia. Climate, 9(6), 1–17. https://doi.org/10.3390/cli9060096
Bhatta, G. D., Aggarwal, P. K., & Shrivastava, A. (2015). Livelihood diversification and climate change adaptation in Indo-Gangetic plains: implication of rainfall regimes. Journal of Agriculture and Environment, 16(June), 77–94. https://doi.org/10.3126/aej.v16i0.19841
Bhutiyani, M. R., Vishwas S. K. & Pawar, N. J. (2007). Long-term trends in maximum, minimum and mean annual air temperatures across the Northwestern Himalaya during the twentieth century. Climate Change, 85, 159–177. https://doi.org/10.1007/s10584-006-9196-1
Birara, H., Pandey, R. P., & Mishra, S. K. (2018). Trend and variability analysis of rainfall and temperature in the tana basin region, Ethiopia. Journal of Water and Climate Change, 9(3), 555–569. https://doi.org/10.2166/wcc.2018.080
Chakraborty, P. D., Chandra, B., & Viswavidyalaya, K. (2008). Lx r ~ : 36(3), 3–6.
Chakraborty, S., Pandey, R. P., Chaube, U. C., & Mishra, S. K. (2013). Trend and variability analysis of rainfall series at Seonath River Basin, Chhattisgarh (India). International Journal of Applied Sciences and Engineering Research, 2(4), 425–434. https://doi.org/10.6088/ijaser.020400005
Chang, K. T. (2016). Introduction to Geographic Information System (Eighth). McGraw-Hill Higher Education.
Chettri, N., Tsering, K., Shrestha, A., & Sharma, E. (2018). Ecological Vulnerability to Climate Change in the Mountains: A Case Study from the Eastern Himalayas. Plant Diversity in the Himalaya Hotspot Region, January.
Gao, C. (2021). Genome engineering for crop improvement and future agriculture. Cell, 184(6), 1621–1635. https://doi.org/10.1016/j.cell.2021.01.005
Gerlitz, J. Y., Macchi, M., Brooks, N., Pandey, R., Banerjee, S., & Jha, S. K. (2017). The Multidimensional Livelihood Vulnerability Index–an instrument to measure livelihood vulnerability to change in the Hindu Kush Himalayas. Climate and Development, 9(2), 124–140. https://doi.org/10.1080/17565529.2016.1145099
Getahun, G. W., Zewdu Eshetu, & Mekuria Argaw. (2016). Temporal and spatial variability of rainfall distribution and evapotranspiration across altitudinal gradient in the Bilate River Watershed, Southern Ethiopia. African Journal of Environmental Science and Technology, 10(6), 167–180. https://doi.org/10.5897/AJEST2015.2029
Ghosh, M., & Ghosal, S. (2021). Climate change vulnerability of rural households in flood-prone areas of Himalayan foothills, West Bengal, India. Environment, Development and Sustainability, 23(2), 2570–2595. https://doi.org/10.1007/s10668-020-00687-0
Government of Sikkim. (2011). Sikkim Action Plan on Climate Change (2012-2030). March 2011, 167.
Greve, P., Gudmundsson, L., & Seneviratne, S. I. (2018). Regional scaling of annual mean precipitation and water availability with global temperature change. Earth System Dynamics, 9(1), 227–240. https://doi.org/10.5194/esd-9-227-2018
Guhathakurta, P. & Revadekar, J. (2017). Observed Variability and Long-Term Trends of Rainfall Over India. In Observed Climate Variability and Change over the Indian Region (pp. 1–16). Ministry of Earth Sciences, Government of India. https://doi.org/10.1007/978-981-10-2531-0
Gunawat, A., Sharma, D., Sharma, A., & Dubey, S. K. (2022). Assessment of climate change impact and potential adaptation measures on wheat yield using the DSSAT model in the semi-arid environment. Natural Hazards, 111(2), 2077–2096. https://doi.org/10.1007/s11069-021-05130-9
Gupta, A. K., Negi, M., Nandy, S., Kumar, M., Singh, V., Valente, D., Petrosillo, I., & Pandey, R. (2020). Mapping socio-environmental vulnerability to climate change in different altitude zones in the Indian Himalayas. Ecological Indicators, 109(October 2019), 105787. https://doi.org/10.1016/j.ecolind.2019.105787
Hänsel, S., Schucknecht, A., & Matschullat, J. (2016). The Modified Rainfall Anomaly Index (mRAI)—is this an alternative to the Standardised Precipitation Index (SPI) in evaluating future extreme precipitation characteristics? Theoretical and Applied Climatology, 123(3–4), 827–844. https://doi.org/10.1007/s00704-015-1389-y
Hansun, S. (2013). A new approach of moving average method in time series analysis. 2013 International Conference on New Media Studies, CoNMedia 2013. https://doi.org/10.1109/conmedia.2013.6708545
Health Indicators. (2011). Health & Family Welfare Department, Government of Sikkim. https://sikkim.gov.in/DepartmentsMenu/health-family-welfare-department/State Health Profile/demographic-indicators
Hossain, M. A., Amin, M. N., Sultana, J., & Siddique, M. N. A. (2020). Climate Change Impact on Agriculture and Related Sustainable Land Management Practices in Bangladesh – A Review. International Journal of Environment and Climate Change, 10(2), 53–69. https://doi.org/10.9734/ijecc/2020/v10i230181
Hussain, A., Agrawal, N. K., & Leikanger, I. (2016). Action for Adaptation: Bringing climate change science to policy makers - a synthesis report of a conference held in Islamabad on 23–25 July 2015. Food Security, 8(1), 285–289. https://doi.org/10.1007/s12571-015-0529-7
IPCC. (2021). Climate Change 2021: The Physical Science Basis: Summary for Policymakers Technical Summary Frequently Asked Questions Glossary. In Intergovernmental Panel on Climate Change. https://www.ipcc.ch/report/ar6/wg1/
IPCC. (2023). Sixth Assessment Report (AR6) Synthesis Report: Climate Change 2023. An Assessment of the Intergovernmental Panel on Climate Change, 335(7633), 1–85. https://www.ipcc.ch/report/ar6/syr/
Kakkar, A., Rai, P. K., Mishra, V. N., & Singh, P. (2022). Decadal trend analysis of rainfall patterns of past 115 years & its impact on Sikkim, India. Remote Sensing Applications: Society and Environment, 26(May 2021). https://doi.org/10.1016/j.rsase.2022.100738
Karavitis, C. A., Alexandris, S., Tsesmelis, D. E., & Athanasopoulos, G. (2011). Application of the Standardized Precipitation Index (SPI) in Greece. Water (Switzerland), 3(3), 787–805. https://doi.org/10.3390/w3030787
Kumar, P., Rupa Kumar, K., Rajeevan, M., & Sahai, A. K. (2007). On the recent strengthening of the relationship between ENSO and northeast monsoon rainfall over South Asia. Climate Dynamics, 28(6), 649–660. https://doi.org/10.1007/s00382-006-0210-0
Kumar, P., Sharma, M. C., Saini, R., & Singh, G. K. (2020). Climatic variability at Gangtok and Tadong weather observatories in Sikkim, India, during 1961–2017. Scientific Reports, 10(1), 1–12. https://doi.org/10.1038/s41598-020-71163-y
Lama, M. P. (2001). Sikkim Human Development Report.
Larson, M. G. (2008). Analysis of variance. Circulation, 117(1), 115–121. https://doi.org/10.1161/CIRCULATIONAHA.107.654335
Lee, S. G., Kim, S. K., Lee, H. J., Choi, C. S., & Park, S. T. (2016). Impacts of climate change on the growth, morphological and physiological responses, and yield of Kimchi cabbage leaves. Horticulture Environment and Biotechnology, 57(5), 470–477. https://doi.org/10.1007/s13580-016-1163-9
Livada, I., & Assimakopoulos, V. D. (2007). Spatial and temporal analysis of drought in Greece using the Standardized Precipitation Index (SPI). Theoretical and Applied Climatology, 89(3–4), 143–153. https://doi.org/10.1007/s00704-005-0227-z
Macchi, M., Gurung, A. M., & Hoermann, B. (2015). Community perceptions and responses to climate variability and change in the Himalayas. Climate and Development, 7(5), 414–425. https://doi.org/10.1080/17565529.2014.966046
Maure, D., Kittel, C., Lambin, C., Delhasse, A., & Fettweis, X. (2023). Spatially heterogeneous effect of climate warming on the Arctic land ice. Cryosphere, 17(11), 4645–4659. https://doi.org/10.5194/tc-17-4645-2023
McDowell, J. Z., & Hess, J. J. (2012). Accessing adaptation: Multiple stressors on livelihoods in the Bolivian highlands under a changing climate. Global Environmental Change, 22(2), 342–352. https://doi.org/10.1016/j.gloenvcha.2011.11.002
Michaels, P. J., Balling, R. C., Vose, R. S., & Knappenberger, P. C. (1998). Analysis of trends in the variability of daily and monthly historical temperature measurements. Climate Research, 10(1), 27–33. https://doi.org/10.3354/cr010027
Mishra, P. K., Rai, A., & Rai, S. C. (2020). Land use and land cover change detection using geospatial techniques in the Sikkim Himalaya, India. Egyptian Journal of Remote Sensing and Space Science, 23(2), 133–143. https://doi.org/10.1016/j.ejrs.2019.02.001
Nandargi, S., & Dhar, O. N. (2011). Evénements de précipitations extrêmes dans l’Himalaya, entre 1871 et 2007. Hydrological Sciences Journal, 56(6), 930–945. https://doi.org/10.1080/02626667.2011.595373
Oakes, T. (2009). Asia. In International Encyclopedia of Human Geography: Volume 1-12 (Vols. 1–12). https://doi.org/10.1016/B978-008044910-4.00250-9
Ojo, O. I., & Ilunga, M. F. (2017). The Rainfall Factor of Climate Change Effects on the Agricultural Environment: A Review. American Journal of Applied Sciences, 14(10), 930–937. https://doi.org/10.3844/ajassp.2017.930.937
Preethi, B., Mujumdar, M., Kripalani, R. H., Prabhu, A., & Krishnan, R. (2017). Recent trends and tele-connections among South and East Asian summer monsoons in a warming environment. Climate Dynamics, 48(7–8), 2489–2505. https://doi.org/10.1007/s00382-016-3218-0
Priya, P., Singh, B.B. & Bisht, J. (2022). Extreme Storms. In Assessmemt of Climate Change over Indian Region (pp. 155–174). Ministry of Earth Science, Government of India. https://doi.org/https://doi.org/10.1007/978-981-15-4327-2
Rao, K.K., Priya, P., Gandhi, N., Bhaskar, P., Buri, V.K. & Sabade, S. S. (2022). Precipitation Changes in India. In Assessmemt of Climate Change over Indian Region (pp. 47–72). Ministry of Earth Science, Government of India. https://doi.org/https://doi.org/10.1007/978-981-15-4327-2
Raziei, T. (2021). Revisiting the Rainfall Anomaly Index to serve as a Simplified Standardized Precipitation Index. Journal of Hydrology, 602(March), 126761. https://doi.org/10.1016/j.jhydrol.2021.126761
Roxy, M. K., Ritika, K., Terray, P., & Masson, S. (2014). The curious case of Indian Ocean warming. Journal of Climate, 27(22), 8501–8509. https://doi.org/10.1175/JCLI-D-14-00471.1
Sawyer, S. F. (2009). Analysis of Variance: The Fundamental Concepts. Journal of Manual & Manipulative Therapy, 17(2), 27E-38E. https://doi.org/10.1179/jmt.2009.17.2.27e
Schröder, L. S., Bhalerao, A. K., Kabir, K. H., Scheffran, J., & Schneider, U. A. (2024). Managing uphill cultivation under climate change – An assessment of adaptation decisions among tribal farmers in Nagaland state of India. Journal of Environmental Management, 349(April 2023). https://doi.org/10.1016/j.jenvman.2023.119473
Sharma, R. K. & Shreshtha, D. G. (2016). Climate perceptions of local communities validated through scientific signals in Sikkim Himalaya, India. Environmental Monitoring and Assessment, 188(578), 1–11. https://doi.org/10.1007/s10661-016-5582-y
Sharma, G., & Rai, L. K. (2012). Climate Change and Sustainability of Agrodiversity in Traditional Farming of the Sikkim Himalaya. Climate Change in Sikkim Patterns Impacts, and Initiatives, 1, 193–218.
Sharma, S., Suwa, R., Ray, R., & Mandal, M. S. H. (2022). Correction: Successive Cyclones Attacked the World’s Largest Mangrove Forest Located in the Bay of Bengal under Pandemic (Sustainability, (2022), 14, (5130), 10.3390/su14095130). Sustainability (Switzerland), 14(15). https://doi.org/10.3390/su14159176
Shrestha, U. B., Gautam, S., & Bawa, K. S. (2012). Widespread climate change in the Himalayas and associated changes in local ecosystems. PloS One, 7(5), 1–10. https://doi.org/10.1371/journal.pone.0036741
Sietsma, A. J., Ford, J. D., Callaghan, M. W., & Minx, J. C. (2021). Progress in climate change adaptation research. Environmental Research Letters, 16(5). https://doi.org/10.1088/1748-9326/abf7f3
Sikkim Statistics. (2013). Government of Sikkim. https://sikkim.gov.in/KnowSikkim/statistics/sikkim-statistics
Singh, V., & Goyal, M. K. (2016). Analysis and trends of precipitation lapse rate and extreme indices over north Sikkim eastern Himalayas under CMIP5ESM-2M RCPs experiments. Atmospheric Research, 167, 34–60. https://doi.org/10.1016/j.atmosres.2015.07.005
Staudt, A., Leidner, A. K., Howard, J., Brauman, K. A., Dukes, J. S., Hansen, L. J., Paukert, C., Sabo, J., & Solórzano, L. A. (2013). The added complications of climate change: Understanding and managing biodiversity and ecosystems. Frontiers in Ecology and the Environment, 11(9), 494–501. https://doi.org/10.1890/120275
Thornton, P. K., Loboguerrero, A. M., Campbell, B. M., Mercado, L., Shackleton, S., & Kavikumar, K. S. (2019). Rural Livelihoods, food security and rural transformation under climate change. 48. http://www.indiaenvironmentportal.org.in/files/file/RuralLivelihoodsFoodSecurityRuralTransformation.pdf
Types, L. U., & Area, G. (2014). Sikkim 11.24.1. 233–241.
Umar, D. A., Ramli, M. F., Aris, A. Z., Jamil, N. R., & Aderemi, A. A. (2019). Evidence of climate variability from rainfall and temperature fluctuations in semi-arid region of the tropics. Atmospheric Research, 224(March), 52–64. https://doi.org/10.1016/j.atmosres.2019.03.023
Upadhyay, A., Nigam, N. K., Mishra, P. K., & Rai, S. C. (2024). Climatic variability and its impact on the indigenous agricultural system using panel data analysis in the Sikkim Himalaya, India. Environmental Monitoring and Assessment, 196(1). https://doi.org/10.1007/s10661-023-12193-7
Upadhyay, A., & Rai, S. C. (2023). Climate Change Analysis in Rangit Basin of Sikkim Himalaya. Oriental Anthropologist, 23(1), 103–130. https://doi.org/10.1177/0972558X221147205
Varikoden, H., Vishnu, S., Koteswararao, K., & Ramarao, M. V. S. (2022). Synoptic Scale Systems. In Assessmemt of Climate Change over Indian Region (pp. 143–154). Ministry of Earth Science, Government of India. https://doi.org/https://doi.org/10.1007/978-981-15-4327-2
Vellore, R., Priya, P., Boregaonkar, H.P. & Singh, B. B. (2022). Climate Change over the Himalayas. In Assessmemt of Climate Change over Indian Region (pp. 207–222). Ministry of Earth Science, Government of India. https://doi.org/https://doi.org/10.1007/978-981-15-4327-2
Xu, J., Grumbine, R. E., Shrestha, A., Eriksson, M., Yang, X., Wang, Y., & Wilkes, A. (2009). The melting Himalayas: Cascading effects of climate change on water, biodiversity, and livelihoods. Conservation Biology, 23(3), 520–530. https://doi.org/10.1111/j.1523-1739.2009.01237.x
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Jyotirmayee Sarkar, Yash Nayan, Amrita Dwivedi (Author)
This work is licensed under a Creative Commons Attribution 4.0 International License.
