Assessment of climate extremes and its long term spatial variability over the Jharkhand state of India

Abstract

This study examines the spatial climatic variability and climate extremes over the state of Jharkhand during 1984 to 2014. The climate extremes and the long-term fluctuation of climate parameters viz. maximum temperature, minimum temperature, rainfall, and solar radiation were assessed using least squares statistical method, for 71 locations in Jharkhand and interpolated spatially in Geographical Information System. The spatial analysis of the trend maps and climate index maps, demonstrates the regions with increasing number of summer days, increasing trend of maximum temperature and solar radiation, decreasing rainfall and thereby increased periods of consecutive dry days during monsoon season. The negative impact of climate extremes was observed as delay in transplanting/vegetative phase and reduced crop production, whereas an increase in the frequency of heat waves with 29 instances during 2004, 41 during 2005 and 100 during 2010 were observed. The findings of this study showed that average maximum temperature during 1984 to 2014 fluctuates with an increase of 1–1.5 °C to a decrease of 0.82–0.14 °C whereas the average minimum temperature fluctuates with a decrease of 0.79–0.39 °C to an increase of 0.59–0.41 °C. Rainfall fluctuates with a decrease of 26–270 mm to an increase of 19–440 mm. The highest average number of summer days is observed in Simdega with 340–348 days whereas the average consecutive dry days for the whole of Jharkhand has an increasing trend particularly in Palamu, Garhwa and Latehar districts, with 3.8–4.2 days of dryness during monsoon. Keywords: Summer days index, Consecutive dry days, Spatial climate variability, Trend analysis