The Distribution of Precipitation and Rain Days over the Tianshan Mountains in Northwest of China

Analysis of precipitation is important to hydrologists and forecasters over mountain, especially in the arid and semi-arid regions of the world. The distribution of precipitation and rain days are analyzed based on 31 stations during the period from 1960 to 2018 in Tianshan Mountains. The results is show that the precipitation and precipitation days is significantly affected by topography in Tianshan mountains. The pattern of precipitation is increased from southern to northern, from eastern to western. High precipitation and precipitation days are located in the Ili Valley. The precipitation and precipitation days are increase with elevation increase decrease with longitude increase. But, the relationship is different between precipitation and rain days with latitude in south and north slope over Tianshan mountains.