Decreasing trend in the rainfall of Kerala

Abstract

The rainfall time series of 75 rain recording stations over Kerala for the 80-year period 1901 to 1980 have been statistically examined for long-term trends. Application of Mann-Kendall rank statistic test to the time series of annual and seasonal totals as well as extreme rainfall of 1, 2, 3...10 day durations revealed a significant decreasing trend in the rainfall over the eastern high lands and adjacent areas to the west. This finding is supported by the fact that the mean rainfall for the second half of the period is 10 to 20% lower than for the first half over the same area.