基于TRMM 3B43 V7数据雅鲁藏布江流域降水空间分异特征分析

Analysis on Spatial Differentiation of Precipitation in the Yarlung Zangbo River Basin Based on TRMM 3B43 V7 Data

为厘清不同时间尺度下雅鲁藏布江流域降水空间分异特征,基于1998—2015年TRMM 3B43 Version7降水数据,分析了年、季、月3个不同时间尺度下流域降水空间分异特征。结果表明:1)雅鲁藏布江流域年降水整体呈东多西少的分布特征。降水高值区位于雅鲁藏布大峡谷一带,达3333.5 mm;低值区位于西部仲巴一带,仅277.4 mm。2)雅鲁藏布江流域季节降水具有夏季多、冬季少、春秋季均衡的特征。夏季,流域内分布着多个“西南—东北”走向的多雨带,且其强度和范围自东向西不断减小。3)TRMM逐月降水数据不但印证了3月—4月流域东部林芝—波密—墨脱一带的“早春雨”现象,同时揭示了5月—8月流域多雨带自东向西的推进过程和各地雨季开始及持续时间的差异。研究结果有助于掌握流域降水多尺度变化特征,也可为进一步探究流域水循环演变规律以及合理开发利用流域水资源提供借鉴。

In order to clarify the spatial differentiation characteristics of precipitation in the Yarlung Zangbo River Basin at different time scales,the author analyzes the spatial differentiation characteristics of precipitation at annual,seasonal and monthly scales based on TRMM 3B43 Version7 precipitation data from 1998 to 2015 in the Yarlung Zangbo River Basin.The results are as follows.1)Annual precipitation in the Yarlung Zangbo River Basin is more in the east and less in the west.The precipitation high value area is in the Yarlung Zangbo Grand Canyon,with the precipitation up to 3333.5 mm,while the low precipitation area is in the Zhongba area in the west,only 277.4 mm of precipitation.2)The seasonal precipitation in the Yarlung Zangbo River Basin is more in summer,less in winter and balanced in spring and autumn.In summer,there are several“southwest to northeast”rain belts in the basin,and their intensity and range are decreasing from the east to the west.3)The TRMM monthly precipitation data not only confirm the phenomenon of“early spring rain”in the Linzhi-Bomi-Motuo area of the east of the basin from March to April,but also reveal the progress of the rainy belts moving from the east to the west from May to August and the difference of the onset and duration of rainy season in different regions.The results can help us to understand the characteristics of precipitation in the basin at multiple scales,and provide reference for further research on the evolution law of water cycle and rational development and utilization of water resources in the basin.