Trend Analysis of Annual Rainfall in Bastar Plateau and Northern Hill Zones of Chhattisgarh, India

Abstract

This study was to find out the trend of annual rainfall for 11 districts of Bastar plateau and the Northern hill zone of Chhattisgarh. Long-term rainfall data of (27 years) in respective districts were collected from the Department of Agro-meteorology. IGKV, Raipur (Chhattisgarh). The trend analysis of rainfall was computed with the help of the Mann-Kendall method and linear trend graph method. Results revealed that the annual rainfall of two districts i.e. Sukma and Kondagaon of the Bastar plateau zone recorded a significant increasing trend at a 5 % level of significance whereas two districts i.e. Bastar and Bijapur were showing a significant increasing trend at a 1 % level of significance. Jashpur district of Northern hill zone shows a significantly decreasing trend at a 5 % level of significance whereas rest five districts i.e. Dantewada, Narayanpur, Surguja, Surajpur, and Koria districts reported non-significant. Two districts showed a non-significant increasing trend i.e. Narayanpur and Balrampur districts. The maximum number of districts reported more or less stable rainfall during the years. On an annual basis, the Bijapur district recorded the maximum amount of rainfall i.e. 3144.5 mm in a year while the lowest rainfall was 511.4 mm in the Dantewada district. The maximum average annual rainfall over the study period was 1624.7 mm in the Sukma district and the lowest average annual rainfall was 1029.5 mm (in 17 years data set) in the Balrampur district.