Abstract: By employing the precipitation observation from 6 representative stations (Lhasa,Shigatse,Zedang,Dingri,Jiangzi,and Langkazi) reanalysis datasets over the Yarlung Zangbo River Valley (YZRV) of Tibet province,China,we analyzed the characteristics of variations in summertime precipitation during 1963 to 2014.The main conclusions are as follows:
From 1963 to 2014,the summer (JJA) precipitation from 6 stations spanned between 221.4 to 355.4 mm,accounting for 71%~85.5% of annual mean precipitation (between 286 and 447.9 mm).Among these stations,the Lhasa received the largest amount of precipitation annually,followed by the Shigatse and Zedang,while the Dingri and Jiangzi in the west reaches of Yarlung Zangbo River had the least annual mean precipitation;the spatial distribution of the summer precipitation is nearly the same as the annual mean.Generally,it showed an increasing trend with obvious inter-annual and inter-decadal variation characteristics of the annual precipitation over the entire YZRV region,among which summer precipitation contributed to most proportion (77%).And the variation of the summer precipitation (from June to August) indicated an increasing tendency in general,which is in line with the variation of the annual precipitation.It can be seen that the variation trend of summer precipitation in Lhasa,Dingri,Shigatse,and Langkazi is the same with the variation trend of the entire YZRV region,especially the variation trend in Lhasa,yet the variation trend in Zedang,Jiangzi showed an decreasing trend.The YZRV region had a significant abrupt change in 1998 in terms of annual mean precipitation,while during the 21st century,there was also short-time-period abrupt phenomenon.It observed that the variation period of summer precipitation in YZRV region were mainly 2~4a and 7~8a.