Statistical Analysis of the Rainfall of Four Major Districts of Gujarat State of India

Abstract

In this research, An Agroclimatic Zone – II of Gujarat state has been considered for the research work. The aim of research work is to carry out the rainfall anomaly index analysis. This zone contains 4 major districts namely Bharuch, Narmada, Surat & Tapi.  Bharuch, Narmada, Surat & Tapi are having 8, 4, 9 & 4 numbers of rain gauge stations respectively. Total 25 number of rain gauge stations data have been used for the analysis purpose. The rainfall anomaly index analysis has been carried out using R-software Programming in which Kalman Smoothing & Arima Model and rainfall anomaly index method were used, for which Kalman Smoothing & Arima Model method and rainfall anomaly index methods ‘imputeTS’ and ‘precintcon’ packages used in R-software. Imputation of data carried out with the help of ‘imputeTS’ package. As per the rainfall anomaly index at 4 & -4, the extreme highest rainfall receiving years were 1976, 2005, 2006, 2013 and 2019 while the extreme reduction in rainfall years were 1986, 1987, 2000 and 2005 over last 47 years. Hansot, Jhagadia, Ukai, and Songadh had received the extreme highest rainfall while Bharuch, Jhagadia, Valod and Vyara had received the extreme reduction in rainfall over the last 47 years. Jhagadia is the common station having highest and lowest rainfall on both scales in same time period.