Statistical Analysis of Rainfall During the Monsoons in the Chaliyar River Basin in Kerala

Abstract

A statistical analysis of monthly mean and daily maximum rainfall data at Kottaparambu
meteorology station of the Center for Water Resources Development and Management
(CWRDM) in Kozhikode district of Kerala, India during the southwest (June-September) and
northeast (October-December) monsoons for a period of 25 years (1981–2005) is presented.
From the analysis, it is observed that a good correlation exists between the daily and monthly
maximum rainfall. A linear regression analysis is also performed for the data and it is found
to be significant for all the seven months. Variance was found to exist between some key
statistical parameters like the mean values of Coefficient of Variability (CV), Relative
Variability (RV) and Percentage Inter-annual Variability (PIV). However, their
corresponding ratios between mean daily maximum and mean monthly rainfall are
significantly lower.