Trend analysis of temperature and precipitation in the Syr Darya Basin in Central Asia

By investigating temperature and precipitation data from eight meteorological stations in the Syr Darya Basin (SDB) during 1881-2011 and 1891-2011, we analyzed trends using the Mann-Kendall (MK) test. Our results indicated that there was a notable increasing trend in annual temperature of 0.14 degrees C/decade (P<0.05) and step change points in 1989 (P<0.05). Similarly, annual precipitation showed a significant rising trend (P<0.001) at a rate of 4.44 mm/decade and step change points in 1991 (P<0.05). Overall, temperature and precipitation increases were more rapid in the plains than in the mountain areas, Furthermore, we found that temperature in the SDB region is strongly associated with the Asian Polar Vortex Area Index (APVAI, correlation coefficient: R=0.701, P<0.01) rather than with carbon dioxide emissions, especially in the plains area. For precipitation, the correlation coefficient is strongly associated with the Tibet Plateau Index (TPI. R=0.490, P<0.01), followed by the Antarctic Oscillation Index (AAOI, R=0.343, P<0.01), and the correlations in the plains are higher than those in the mountains. It is anticipated that the results of this study will further the understanding surrounding climate change in the SDB.