Geographia Polonica (2003) vol. 76, iss. 2

Trends and periodicity in the longest instrumental rainfall series for the area of most extreme rainfall in the world, Northeast India

Paweł Prokop, Adam Walanus

Geographia Polonica (2003) vol. 76, iss. 2, pp. 25-35 | Full text

Abstract

The longest instrumental rainfall series have been investigated for the North Assam subdivision and 4 meteorological stations in Northeast India. Analysis of trends to annual and seasonal rainfall show these to be very stable, with no change in the rainfall over North Assam during the last 150 years. The Fourier analysis of fluctuations in rainfall series shows that the periodic signal of T=3.5 year is the strongest one. Such a signal, with the same phase, has been found for all rainfall stations of the North Assam subdivision and in all investigated seasons.

Keywords: monsoon rainfall, trend, periodicity, northeast India

Paweł Prokop [pawel@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Adam Walanus, Institute of Archaeology, University of Rzeszów, Hoffmanowej 8, 35-016 Rzeszów