黄河源区气候变化与GLDAS数据适用性评估

Climate Change and Applicability of GLDAS in the Headwater of the Yellow River Basin

利用观测资料分析了1979—2010年黄河源区气温、降水量及流量变化;验证了全球陆面同化系统(GLDAS)数据在黄河源区的适用性并用其分析了水循环变化特征。结果表明,GLDAS气温数据能够指示源区近30年尤其是近10年来气温升高及空间上从西向东逐渐升高的分布规律。GLDAS降水数据也能够描述源区降水量从东南部向西北部逐渐减少的空间分布特征。1979—2010年唐乃亥水文站年平均流量呈下降趋势,但在近10年年平均流量有所回升。GLDAS中的CLM模式描述出了源区"先降后升"的水循环变化规律。尽管近10年来径流系数有所回升,但是1979—2010年黄河源区径流系数整体呈下降趋势。

Changes of surface air temperature, precipitation and discharge in 1979-2010 are analyzed over the headwater of Yellow River Basin （HYR）. Applicability of the Global Land Data Assimilation System （GLDAS） re- analysis data is evaluated compared to observations. Further, major variables of the water cycle in the HYR are an- alyzed using GLDAS. The followings are obtained. Significant warming has been observed in the HYR, particularly in recent 10 years. The surface air temperature is higher in eastern HYR than in western HYR. GLDAS agrees well with the observation in surface air temperature change and pattern. Precipitation increases gradually from northwest to southeast HYR. GLDAS matches well with mean precipitation distribution in 1979-2010, especially before 2000. Discharge at the Tangnag Station decreases in 1979-2010. Annual discharge is still under average level in the HYR although it increases after 2000. The runoff simulation in CLM matches observation at the Tangnag Station better than other models. Runoff coefficient shows a general decreasing trend in 1979-2010 despite the recovery after 2001.