GRACE反演近年青藏高原及雅鲁藏布江流域陆地水储量变化

Inversion of terrestrial water storage changes in recent years for Qinghai-Tibetan plateau and Yarlung Zangbo River basin by GRACE

利用2005年至2010年6年的GRACE(Gravity Recovery and Climate Experiment)数据反演,研究了青藏高原地区以及雅鲁藏布江流域的季节及年陆地水储量的变化情况。结果显示:在研究区,伴随着显著地季节性波动,年水储量均有明显的下降趋势。同时,流域GRACE数据反演结果和国际上几种模式的水文模拟结果比较表明,GRACE在两个流域上的反演结果与CPC水文模型模拟结果变化趋势较为一致,但水储量年、季变化幅度偏大,而与GLDAS发布的CLM与VIC模型的结果则相差甚远,主要原因归结为青藏高原地区气候条件复杂导致模型的不确定性及误差较大,而大多水文模型缺乏对地下水变化的模拟能力所致。

With the GRACE（Gravity Recovery and Climate Experiment） data from 2005 to 2010,terrestrial water storage changes of Qinghai-Tibetan Plateau and Yarlung Zangbo River Basin were inversed and systematically analyzed.The preliminary results indicated a persistent decreasing trend in the yearly terrestrial water storage level with significant seasonal fluctuation in the study region.Comparisons of GRACE based inversions with those simulated by internationally well-known hydrological models suggested the significant discrepancies existed either for yearly or for seasonally terrestrial water storage changes.In general,CPC model simulated quite similar variation treads compared to GRACE reversed but with a smaller fluctuation magnitude.However,both CLM and VIC models released by GLDAS give quite different outputs compared with that reversed by GRACE.The discrepancy is mainly attributed to the shortcomings in ground water variation simulations for the most of hydrological models.Moreover,the complex meteorological,hydrological and the underneath conditions in Qinghai-Tibetan Plateau usually result in errors for hydrological simulations.