Estimation of distribution of cumulative rainfall for a specific period within a Njattuvela

Abstract

A stochastic model for determination of time distribution of cumulative rainfall for a specific period within a njattuvela was worked out by making use of the daily rainfall data collected from the Regional Agricultural Research Station, Kerala Agricultural University, Kumarakom. A day having a minimum of 3 mm of rainfall was regarded as a wet day. The daily rainfall depth within a njattuvela was characterised using an exponential distribution. Further the first and second order Markov chain models were fitted to the data. Thechi-square test for adequacy of f i t revealed that the first order was the best fit. Using the first and second order Markov chain probabilities, the cumulative rainfall depth of at least a reasonable amount was worked out. The study thus brought out that the significance of stochastic models for characterisation of time, distribution of rainfall depth.