Statistical analysis of rainfall trends over Damodar River basin, India

Abstract

This paper is intended to compute long-term spatiotemporal variability of precipitation on annual and seasonal scale of Damodar River Basin over the period of 113 years (1901–2013). The lag-1 autocorrelation coefficient was applied to check serial dependence in the dataset. After this, non-parametric Mann Kendall and modified Mann Kendall test were used to identify trends and the Theil-Sen’s slope method to estimate magnitude of trend line. Sequential Mann Kendall test was also applied to detect the potential turning point. Results found significant decreasing precipitation trend in annual and monsoon season over the basin except the southeastern part. The maximum decrease was found for annual and monsoon season at the northwestern part while minimum at the northeastern region. The sequential Mann Kendall test identified several non-significant as well as significant turning points for seasonal and annual rainfall at most of the locations.