A Preliminary Study on Trends and Interannual Variaration ofPrecipitation in Central and Western Portions ofNorthwest Region of China
XIE Jin-nan\+1,ZHOU Jia-ling\+2(1. Meteorological Bureau of Gansu Province, Lanzhou 730020, China; 2. Nanjing Institute of Meteorology, Nanjing 210044, China)
The trends and interannual variation of precipitation in Northwest China are studied by using the trend coefficient and moving t-test technique based on the (1951\_1998) observation data at 22 stations located in the Northwest Region of China. The results show that there exists descending trends of precipitation on the northeast side of Qinghai-Xizang Plateau during recent half a century, especialy during recent 10 years.