Spatio-temporal Analysis of Climate Change in Kerala, India: Implication for Cardamom Production
R. S. Neethu *
College of Agriculture, Vellayani, Kerala Agricultural University, Trivandrum-695304, India.
Sreehari V. Santhosh
Indian Agricultural Research Institute, New Delhi – 110012, India.
Pradeep Krishnamurthy
Indian Agricultural Research Institute, New Delhi – 110012, India.
B. Devi Priyanka
College of Agriculture, Raipur, Indira Gandhi Krishi Vishwavidyalaya-492012, India.
V. Kumar
Indian Agricultural Research Institute, New Delhi – 110012, India.
Brigit Joseph
College of Agriculture, Vellayani, Kerala Agricultural University, Trivandrum-695304, India.
*Author to whom correspondence should be addressed.
Abstract
The study examined long-term climate change patterns in the central regions of Kerala over a 30-year period. Trend analysis was performed for annual and seasonal variables using Mann–Kendall and Sen’s slope estimator. The results revealed a significant decreasing trend in annual rainfall and northeast monsoon rainfall, accompanied by an increasing trend in maximum temperature during both the southwest and northeast monsoon seasons. Minimum temperature exhibited a declining trend across all seasons except summer and winter. To further assess rainfall variability, Seasonal ARIMA (SARIMA) models were fitted to monthly rainfall data. The best-fit models identified was ARIMA (0,0,0)(0,1,1)₁₂. The findings give an insight into regional climatic variability and offer a scientific basis for long-term agricultural planning and climate adaptation strategies. Multiple regression on production of cardamom as dependent variable and quarterly temperature and rainfall as the independent variables revealed reasonable increase in minimum temperature positively influences the yield of cardamom and excess rainfall during harvesting period had negative impact.
Keywords: Mann-Kendall test, Sen’s slope estimator, SARIMA, Semi log model