Statistical Analysis of Precipitation Over Kota (India) from 1981 to 2020

Abstract

Variation in precipitation amounts and distribution patterns leads to changes in general atmospheric circulation, cloud cover, surface albedo, and concentrations of air pollutants in the context of climatic variability. Industrial, residential, and agricultural water demands largely depend on rainfall. Even rainfall variability significantly affects people's livelihood. This study evaluates the temporal variation in rainfall for the Kota district of Rajasthan state in India. Eight rainfall monitoring stations were utilised to collect precipitation data for 40 years (1981–2020). Trend analysis has been performed for monthly, seasonal, and annual rainfall series with the help of Mann–Kendall (non-parametric) and linear regression (parametric) trend tests. Standardised rainfall anomaly and wetness index were estimated to determine the excess in total annual rainfall. The monthly distribution of precipitation is contrasted with the help of the precipitation concentration index. Both non-parametric and parametric trend tests estimate an increasing trend in precipitation for February, March, June, July, August, and September months, reflecting an increase in the total annual precipitation for the research area. The analysis of precipitation data shows a very high inter and intra variability in annual rainfall (C.V. = 169.45). A very high non-uniformity of rain is observed from the analysis of PCI. The maximum concentration of precipitation (~84.50) took place in monsoon months. Annual rainfall has significantly increased over the last four decades, indicating the need for proper rainwater management and utilisation plans to take maximum benefits shortly.