Spatio-temporal Pattern Variations of Temperature and Precipitation in Northern Parts of the Qilian Mountains and the Nearby Regions from 1965 to 2018

Abstract

The linear regression， Mann-Kendall trend test and Morlet wavelet transform were used to make a detailed analysis on the temporal dynamics and spatial patterns of temperature and precipitation.The temperature and precipitation monitoring data from 12 meteorological stations in the northern slope of Qilian Mountains and its adjacent areas during the period from 1965 to 2018.The results revealed that： （1） The multi-annual mean， maximum and minimum temperatures fluctuated with increase rates of 0.33 ℃·（10a）-1， 0.44 ℃·（10a）-1 and 0.21 ℃·（10a）-1， the temperature changed dramatically in 1998.The multi-annual mean and maximum precipitation fluctuated with increase rates of 4.28 mm·（10a）-1， 16.98 mm·（10a）-1， while the minimum value fluctuated with decrease rates of -4.30 mm·（10a）-1， there was a sudden change in precipitation from less to more in 1971 and 1994.The seasonal variation trend of temperature and precipitation was consistent and continued to rise， and there has a significant increase feature in winter.The interdecadal evolution of the two shows an increasing trend in the 1990s.（2） On the whole， the temperature and precipitation decreased from southeast to northwest， forming a spatial pattern with Zhangye and Gaotai as the dividing line， the temperature and humidity increased faster in the east， and the temperature and humidity increased slower in the west.The overall climate showed a warming and humidity trend.（3） The annual mean temperature has a strong period of 13-year and a period of 6a and 27-year in the scale of 54-year， and there are strong significant periods of 8-year and 20-year and small-scale change periods of 2-year and 27-year.

Keywords

• qilian mountains
• temperature and precipitation
• time series
• spatio-temporal pattern