四套降水资料在喀喇昆仑山叶尔羌河上游流域的适用性分析

Analysis of the Applicability of Four Precipitation Datasets in the Upper Reaches of the Yarkant River,the Karakorum

分析了2003-2009年基于卫星观测的降水数据CMORPH、TMPA 3B42v6、中国科学院青藏高原研究所的融合数据ITPCAS和基于地面台站的APHRODITE(2003-2007)四套降水数据集在叶尔羌河上游流域的时空分布特征,并以这四套降水数据为驱动,利用VIC分布式水文模型对叶尔羌河上游流域的降水径流进行模拟.结果表明:在空间分布上,四套降水资料在叶尔羌河上游流域的差异较大,ITPCAS的空间分布与流域冰川的分布较一致,基于冰川区即为大降水区的基本认知,初步认为ITPCAS的空间分布比较合理;其次是TMPA 3B42v6和APHRODITE;在流域的年降水量和季节分配量上,由于缺乏高海拔地区的实测降水资料,无法准确回答各套降水资料在量级上是否合理;在时间序列上,四套降水资料与流域站点降水(库鲁克栏杆站和塔什库尔干站的平均降水)存在着不同程度的差异.但从整体上看,CMORPH数据在一定程度上能够反映流域的月降水变化过程,而APH-RODITE和ITPCAS只能在个别年份对流域的降水描述较好;在径流模拟上,卫星降水数据CMOR-PH显示了作为水文模型输入数据的较大潜力;而其他降水资料在叶尔羌河径流模拟中,与实测径流在量和季节分配上可能存在较大偏差.

The applicability of four precipitation products to the upper reaches of the Yarkant River is compared.The four datasets are： CMORPH,TMPA 3B42 v6,APHRODITE and ITPCAS.The characteristics of the temporal and spatial distributions of the four precipitation datasets are analyzed for 2003-2009.The datasets are also used as the forcing data to drive the variable infiltration capacity semi-distributed hydrology model.It is found that the spatial distribution of ITPCAS agrees reasonably with glacier distribution,followed by TMPA 3B42 v6 and APHRODITE.Among the four datasets,only CMORPH can roughly follow the seasonal variation of the mean gauge precipitation estimation.Runoff simulations suggest that CMORPH precipitation shows a potential as hydrological model input data for the Yarkant River,while the other precipitation datasets seem to possibly underestimate the precipitation in the catchment.