Block Wise Trend Analysis and Extreme Events in Raipur District, India

Abstract

The study was conducted in four blocks viz. Abhanpur, Arang, Raipur, and Tilda of Raipur district, using IMD gridded rainfall and maximum (Tx) and minimum (Tn) temperature data from 1951 to 2019. Trend analysis was performed with three non-parametric methods (Mann Kendall, Spearman's Rho, and Innovative Trend Analysis (ITA)) and one parametric test (Linear Regression analysis) for annual and seasonal rainfall and temperature. Extreme weather events were studied using Weather Cock and RClimdex software, calculating sixteen climatic indices. The data was divided into 1951-1986 and 1987-2019. The results demonstrated a significant decreasing trend (p<0.01) in rainfall by 10 to 15%. Maximum temperature had a significant increasing trend and minimum temperature significantly decreased (p<0.01) as per ITA. Other methods indicated non-significant decreasing trends for minimum temperature. ITA proved more effective in trend detection. The value of all indices differed before and after 1986, indicating noticeable climate changes. Increasing Warmer days, colder nights, and an expanding diurnal temperature range were observed, accompanied by increased heat wave incidence. Moderate drought episodes and all severe drought occurrences increased after 1986. The values of maximum and minimum temperatures reached new peaks. These findings highlight significant climate changes in the study area, emphasizing the need for sustainable climate management and adaptation strategies.