Qilian Mountains, known as the "Water Tower of the Hexi Corridor", provide main water source of the living and agriculture production in the Hexi Corridor. 

Therefore, variations in precipitation and temperature in the Qilian mountain regions have an important effect on water sources for downstream river.  

However, characteristics and control factors of precipitation and temperature changes in these areas are not well understood, affecting the ability to allocated downstream water resources judiciously. 

Recently, a research group led by Prof. CHEN Rensheng from Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences analyzed the annual and seasonal variability in precipitation and temperature during 1960-2016 using monthly data from 25 national meteorological stations in the Qilian Mountains. 

The study results showed variability in summer precipitation made the greatest contribution to the annual change in precipitation. Moreover, the increment in precipitation was amplified with elevation. 

The result of principal component analysis enhanced westerly circulation and increased water vapor were the factors responsible for the increased precipitation in the study area.  

Besides, changes in temperature were greatest in winter, and changes in winter temperature made the greatest contribution to the annual temperature changes. 

The annual increase in temperature may be affected by carbon emissions, Siberian High, and Arctic Oscillation. In addition, the changes of cloud cover may be also the main cause of changes of temperature. 

The findings will not only deepen the understanding of climate change in the study areas, but also increases the understanding of the hydrologic cycle and formation of water resources. Furthermore, the results are significant for the simulation of runoff and water resources management in the mountains. 

The study entitled "Change characteristics of precipitation and temperature in the Qilian Mountains and Hexi Oasis, Northwestern China" was published in Environmental Earth Sciences. 

 Fig. 1. Distribution of meteorological stations and land cover in the study area. (Image by CHEN Rensheng)  

Fig. 2. Variability amount in precipitation for each decade in the Qilian Mountains from 1960 to 2016. (Image by CHEN Rensheng)  

Fig. 3. Variability amount in temperature in the Qilian Mountains for each decade from 1960 to 2016. (Image by CHEN Rensheng)