羌塘高原降水空间分布及其变化特征  

Spatial distribution and variation of precipitation in the Qiangtang Plateau

作　　者：李兰晖 刘琼欢 张镱锂[1,2] 刘林山 丁明军[3] 谷昌军[1,2] 

机构地区：[1]中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,北京100101 [2]中国科学院大学,北京100049 [3]江西师范大学地理与环境学院鄱阳湖湿地与流域研究教育部重点实验室,南昌330022

出　　处：《地理研究》2017年第11期2047-2060,共14页Geographical Research

基　　金：国家科技基础性工作专项重点项目(2012FY111400);中国科学院战略性先导科技专项(XDB03030500);国家科技支撑计划(2012BAC06B00)

摘　　要：羌塘高原作为典型的青藏高原内流区,其降水变化直接影响自身及其周边区域冰冻圈与生态系统的变化。但由于站点观测资料的限制,羌塘高原降水时空格局尚不明确。因此,基于2015年羌塘高原9个自动观测站逐小时降水数据和5套降水格点产品以及1978-2015年西藏地区26个国家台站逐日降水数据,分析羌塘高原降水的空间分布和变化特征。结果表明:(1)2015年羌塘高原核心区降水量和降水日数的均值分别约为154.9 mm和50天,其中,降水量约为东南边缘以及西藏地区多年均值的1/3和1/4。在空间上,降水量呈现东南多、北部少的特征,其中,昆仑山脉以北地区降水量最低,这从降水角度验证了该区域是"寒旱核心"的主要地区之一。(2)雨季与干季分明。西北部雨季分布在6-8月,比东南边缘地区约短1~2个月;且前者降水量呈现单峰型而后者呈现双峰型。(3)在高原核心区,热带降雨测量计划(TRMM)3B43数据和全球降水量测量计划(GPM)IMERG算法数据高估了多数站点的年降水量,主要是高估了干季降水量所致。(4)1978-2015年羌塘高原改则和狮泉河站降水量和降水日数呈现微弱增加趋势,且强降水事件增多。Qiangtang Plateau（QP） refers as a typical interior region in the Tibetan Plateau,where the variability of precipitation is critical for cryospheric and ecosystems changes.However, the spatial distribution and variation of precipitation in the QP remains poorly understood due to lacking of precipitation gauges data. Based on precipitation data from nine automatic stations and five remote sensing and simulated precipitation products in 2015 and daily precipitation data from twenty-six meteorological stations during 1978-2015 in the QP and its vicinity, the spatial distribution and variation of precipitation were analyzed. Results showed that：（1） Annual precipitation and precipitation days were approximately 154.9 mm and50 days in the core of the QP in 2015, respectively. Annual precipitation in the core of QP was approximately one third and one quarter of the average annual precipitation in the southeast of the QP and Tibet Autonomous Region, respectively. The lowest precipitation is observed on the north slope of the Kunlun Mountains, which confirms that this area is one of the main regions of ＇cold dry core＇ in the perspective of precipitation.（2） The rainy season is clearly different from the dry season. The rainy season exists from June to August in the northern region, whose length is about 1-2 months shorter than that in the southern region. The distribution of precipitation in the northern region shows a single peak while that in the southern region shows a bimodal pattern.（3） TRMM（3 B43） and GPM（IMERG） overestimated the annual precipitation in most sites of the QP, mainly due to the overestimation of precipitation in dry season.（4） A slight wetting process and an increasing trend of heavy rainfall events were detected in local area of the QP from 1978 to 2015.

关 键 词：羌塘高原 降水 TRMM GPM 青藏高原 

分 类 号：P426.6[天文地球—大气科学及气象学]