Climate Change Detection in Guilan Province

In this research study, in order to recover probable local climate changes, time series of monthly and annual precipitation, mean temperature, annual minimum and maximum temperature related to Anzali port and Rasht synoptic stations during the statistical period from 1955 to 2003, and climatological stations with long-term period like Lahijan, Pilimbra and Astara has been studied. Statistical studies of climate change usually analyze homogeneity, trend and jump in the climatic series. In this study, homogeneity of mentioned climatic series was tested by four methods, cumulative deviations, worsley's likelihood ratio, first-order autocorrelation and Bartlett tests. Existing long-term Trend was tested by different parametric and non-parametric tests consist of Mann-Kendall, correlation coefficient Pearson, t-student and Spearman tests. Annual minimum temperature of all stations had a significant increasing trend, though annual mean and maximum temperature for most of them had no significant trend. Precipitation trend in Anzali port was decreasing while in Astara and Lahijan was increasing. Rasht and Pilimbra precipitation had no significant trend. Jump in series was tested by ANOVA and Kruscal-Wallis tests. The year 1994 is start point of increment of temperature. Besides, domain of mean temperature and temperature extreme values has studied. The aim of analyzing time series is determination of long-term behavior of observation data and finding changes model to use for engineering designs and other projects.

کلیدواژه ها:

Astara ، Anzali ، Climate Change ، Guilan ، Homogeneity ، Jump ، Lahijan ، Pilimbra ، Rasht ، Trend