Analysis of Trend in Rainfall Using Non Parametric Statistical Methods

摘要

Identification of trend or persistence in the rainfall series is essential to present the hydrological information in the condensed form for decision-making in water resources planning of any region. This paper exemplifies a study involving non-parametric statistical method of Mann-Kendall test for identification of existence of trends in annual hourly maximum, monthly and annual, and seasonal rainfall series for Kanyakumari and Thiruvananthapuram regions. Sen's estimator of slope method was used to compute the change per unit time in a time series having linear trend. The paper presents the downward trend in the annual rainfall series of the regions covered under study. The paper also presents the upward trend in winter and monsoon seasons of rainfall for Kanyakumari and Thiruvananthapuram regions.