Statistical Analysis of Thirty-Year Rainfall Variability in Udaipur District, Rajasthan, India

Abstract

The rainfall variability for the Udaipur district for thirty years (1991–2020) was statistically analysed in this study. The linear regression (parametric) and Mann–Kendall (non-parametric) trend test along with precipitation indices performed using rainfall data collected from 9 rain gauge stations situated in different parts of the Udaipur district, Rajasthan, India. An increasing trend was found between the months March to November in the Udaipur district, indicating that total annual rainfall has increased in these months during the study period. About 85.20% of the total annual rainfall is occurred due to the southwest monsoon during the rainy season. The PCI (21.74 to 57.92) and CV (11.04 to 21.23) values show the high-nonuniformity and less rainfall variability, respectively. The SRA values for each year have been greater than -0.84 (no drought category) during the study period. The rainfall deficiency took place only four out of 30 years of the study period, 1995, 1999, 2000, and 2002, which fall under the category of large deficiency. The values of the wetness index indicate that during the study period,2006 was the wettest year due to the maximum rainfall (Wi = 179.07) while 2000 was the driest year due to the minimum rainfall (Wi = 54.26). Total annual rainfall has increased in the last three decades, which shows the need for implementation of all necessary plans by the government for proper rainwater utilization and management to prevent future natural disasters like floods.