Abstract:

It has attracted extensive attention that the climate in the arid region of Northwest China is warming and wetting， but further research is needed on the magnitude， trend and spatial performance of this phenomenon. The Hexi Corridor is located in the eastern part of the arid region in China， which is an important area along "the Belt and Road". In this paper， 7 meteorological stations in Wuwei， Minqin， Yongchang， Zhangye， Linze， Gaotai and Jiuquan respectively， located in the plain area of Hexi Corridor， were selected to analyze the characteristics of temperature and precipitation change from 2000 to 2020. The results show that the average temperature has increased by 0.53 ℃/10yr， representing a decreasing trend from east to west； the change rate of average maximum temperature is 0.22 °C/10yr， and the change rate of average minimum temperature is 0.40 °C/10yr. There is no significant change trend in annual precipitation during 2000-2020， but the interannual fluctuation of year rainfall increases. The annual precipitation of <5 mm，5-10 mm， 10-15 mm， 15-20 mm， and >20 mm is 58.8 mm， 38.3 mm， 22.1 mm， 12.7 mm， and 16.1 mm respectively； and each level of precipitation accounts for 39.69%， 25.87%， 14.93%， 8.60% and 10.90% of the annual precipitation. In the past 20 years， the frequency of different precipitation events， their contribution to precipitation， and the number of precipitation days did not change much. The temperature increase in the eastern part of the Hexi Corridor was larger than that in the western part， but the change in precipitation did not show a difference between the eastern part and the western part. Overall， the climate of the Hexi Corridor had a trend of warming in the past 20 years， but the trend of wetting is not obvious.

Key words: Hexi Corridor, temperature, precipitation, precipitation events, precipitation days, warming and wetting