摘要
青藏高原及其周边干旱区的水循环过程对全球变化的响应十分敏感。基于观测资料驱动的全球陆面数据同化系统(GLADS)能为区域尺度水循环变化研究提供更全面的数据。利用GLADS数据,首先对青藏高原及其周边干旱区进行气候区划分,分析了各气候区内气温和降水的时空分布和变化特征;然后检验了GLDAS数据在青藏高原地区的适用性;最后探讨了模拟期间地表水循环关键要素的时空变化特征及区域水资源分配格局。结果表明,各气候区在2000-2007年比1979-1994年平均气温上升了0.65～0.97℃,增幅明显提高。不同区域降水量变化各异,干旱区和半干旱区2000-2007年比1979-1994年平均年降水量分别升高了14mm和25mm。1979-1994年间GLDAS气温、降水数据在青藏高原及其周边地区适用性较高;极端干旱区气温数据与中国地面气温格点数据之间的均方根误差仅为0.41℃;在各气候区GLDAS数据与APHRODITE平均降水差值均小于0.18mm·d-1,但2000-2007年数据质量有待提高。研究时段内研究区域水循环处于动态平衡状态。2000年以来青藏高原及其周边干旱区径流量、蒸发量呈增长趋势的区域明显扩大,且幅度大幅上升,但变化量级存在不确定性。新疆大部分地区水循环变化特征表现为暖干向暖湿转变。青藏高原及其周边干旱区自2000年以来水循环有所加强,降水仍主要用于蒸发,多年平均径流系数大多小于0.2。
Some researches show that the hydrological cycle in the Qinghai-Xizang Plateau and its surround- ing arid area is particularly sensitive to global climate change. Due to the observations of evaporation and runoff are sparse, the hydrological cycle change in the study area is certainly limited. Based on the obser- vation driving data, Global Land Data Assimilation System （GLDAS） represents the regional distribution of surface hydrological cycle element, and also give support to the study of regional scale of hydrological cycle change. Firstly, the four climatic regions are divided the Qinghai-Xizang Plateau and its surrounding arid area, the variation characteristics of temperature and rainfall in each climate zone are analyzed. Then the suitability of temperature and precipitation data of GLDAS four land surface models in 1979--2007 is tested. I.astly the space variation of evaporation and runoff and the change of surface hydrological cycle key elements in different climate zones are discussed. The results show that the average temperature of four climate regions in 2000-- 2007 and 1979-- 1994 ranging from 0.65 to 0.97 ℃, and grew obviously. Precipitation changes differently, mean of which in arid and semi-arid area in 2000--2007 is more than 14 mm and 25 mm in 1979--1994. GLDAS temperature and precipitation data have high applicability in the Qinghai-Xizang Plateau and its surrounding arid area in 1979--1994. The root-mean-square error beteen GLDAS temperature data and Chinese surface grid temperature data in extreme arid area is only 0.41 ℃. The differences beteen GLDAS data and APHRODITE precipitation data in four climate region are all less than 0.18 mm · d^-1 The water cycle in study area is in dynamic balance during the research period. But the data quality of 2000--2007 has yet to be improved. Runoff and evaporation increasing area grew signifi- cantly, and the amplitude have risen sharply, but changing magnitude is uncertain. The change character- istics of hydrological cycle key elements in most areas of Xinjiang Province are consistent with the scientific hypothesis of climatic shift from warm-dry to warm-humid previous proposed. The precipitation of this ar- ea is mainly used for evaporation. In the recent years, the hydrological cycle is strengthened. Multi-year average runoff coefficient are less than 0.2.
出处
《高原气象》
CSCD
北大核心
2013年第3期635-645,共11页
Plateau Meteorology
基金
国家重大科学研究计划(2013CB956004)
中国科学院百人计划项目共同资助
关键词
陆面同化数据
青藏高原及其周边干旱区
水循环
Land assimilation data
Qinghai-Xizang Plateau and the surrounding arid area
Hydrological cycle
